While some good points were made, a lot in that video was over-simplified in order to fit into a 12 minute Youtube videos that people will watch (it's pretty well known that the majority of Youtube viewers tune out after 10-15 minutes).
For example, while Boden and Laack make good points about ballistic gel and its value, Baker tries to justify Lucky Gunner's use of Clear Ballistic gel by saying that the results are "comparable" and that the biggest difference is the temporary cavity. Unfortunately, Mr. Baker doesn't mention that Clear Ballistics gel often retards expansion and increases penetration of a given loading when compared to calibrated 10% Ordinance gel.
As is pointed out, ballistic gel is a model and can't be expected to give an exact 1 to 1 ratio of penetration and expansion when compared to a living organism. What is failed to be mentioned with that calibrated 10% ordinance gel is the industry standard because it is considered to be the closest repeatable approximation that we have to actual living tissue. While other media can give us repeatable results, the less similar they are to actual living tissue the less useful testing with them is. This is why I questioned the usefulness of Lucky Gunner's testing in another thread: the media they chose cannot be trusted to give an accurate approximation of living tissue.
Another issue is Mr. Laack repeating what I refer to as "the magic velocity number" myth. According to Mr. Laack, bullets to not generate a significant enough temporary stretch cavity to overcome the elastic limits of human tissue until they reach the "magic number" of 2200 fps (the "magic number" seems to vary depending on who is quoting it). Because rifle bullets often travel at so much greater velocity than handgun bullets, it is often assumed that velocity is the reason that rifles are more effective. The reason, however, is that rifle bullets typically have much more energy than handgun bullets and increasing velocity is the most efficient (though not only) means of increasing energy.
If the "magic number" of 2200 fps were really the defining characteristic, then a .17 HMR loaded with a 17 gr bullet at 2530 fps should be more effective than a .45-70 loaded with a 300 gr bullet at 1850 fps since the .17 HMR surpasses the 2200 fps "magic number" while the .45-70 does not. Of course we know this is not the case, the .45-70 is more effective because despite its lower velocity, it has much greater energy due to its much heavier 300 gr bullet.
Also, while handgun bullets may not exceed the elastic limits of living tissue much of the time, this certainly isn't the case all the time. Living organisms are not homogenous like ballistic gel and different types of tissues have different elastic limits. Also, some of the more powerful handgun cartridges like .44 Magnum or .454 Casull can create much larger temporary cavities than the more typical service cartridges like 9mm or .45 ACP. Many of these Magnum-class cartridges can produce very impressive temporary cavitation which is comparable to those produced by smaller centerfire rifle cartridges like .223 Remington.
Now, I was willing to give Mr. Laack the benefit of the doubt because he's the head of the law enforcement division and most of what he was saying is consistent with what is typically seen in common law enforcement calibers (few police agencies use .17 HMR, .45-70, or .44 Magnum). That is, I was willing to give the benefit of the doubt until he said that the extra energy of a powerful handgun like a .44 Magnum is "obliterated" or "washed away" by the temporary stretch cavity. Newtonian physics tells us that energy can neither be created nor destroyed, therefore it is impossible for it to be "obliterated" or "washed away". In the example he gives of a .44 Magnum vs. a .40 S&W, the extra energy of the .44 Magnum will translate to either a significantly larger temporary cavity or substantially greater penetration. Now, it is possible that a shot with a .44 Magnum might have little more effect than one with a .40 S&W, but that would likely be because the part of the body struch was one with a high elastic limit like muscle or bowel or because the .44 Magnum was loaded with a bullet that displayed little or no expansion (such as a JSP or LSWC) and simply penetrated through-and-through.
Mr. Boden states that velocity and energy helps to achieve the expansion and penetration that we desire but that they don't 100% correlate with effectiveness and this is correct, but warrants further explanation. Velocity and energy are pieces of the puzzle rather than the answer in and of themselves just as expansion and penetration are pieces of the puzzle. A 90 gr 9mm JHP at 1500 fps will have a lot of energy and will expand violently, but it's generally considered a poor choice because it will likely penetrate shallowly. Likewise, a .38 Special loaded with a 200 gr JHP at 600 fps will probably penetrate quite well, but it's also considered a poor choice because it has little energy and likely won't expand.
Mr. Boden's example of a hot 10mm possibly showing over-penetration or over-expansion and under-penetration is a good example of matching bullet design to velocity. For example, if you loaded a 115 gr .355 Winchester Silvertip (which expands quite easily) in a .357 Sig at high velocity, you'd likely get over-expansion and/or fragmentation and shallow penetration. Just as undesirable, however, would be to load a 115 gr .355 Hornady XTP (which is a "tough" bullet designed for controlled expansion) into a .380 Auto at low velocity as you'd get over-penetration with little or no expansion.
Finally, while only mentioned in passing in the video, most of the standards that so many of us want to judge handgun ammo by are based on the standards set for by the FBI. What is important to remember is that the FBI standards are set with law-enforcement in mind and that the needs of a private individual and those of an LEO are often quite different. For example, while most people only look at, or only know about, the FBI's bare gel and heavy clothing tests, they actually test bullet through a variety of intermediate barriers including drywall, sheet steel, plywood, and auto glass. This is because it is not uncommon for a LEO to engage an enemy who may be seeking cover behind an intermediate barrier.
A private individual, however, would likely be harder pressed to explain why it was necessary to shoot someone through an interior wall or windshield. Because of this, the bare gel and heavy clothing tests are most useful to the private individual. A police agency may very well choose a particular loading that doesn't perform quite as well as another in bare and clothed gel because it is markedly superior in the other intermediate barrier tests.
Also, it seems that too many people get hung up on one particular facet of a bullets performance to the point of forgetting why that facet was desirable to begin with. For example, many people would look down their noses at Remington's 158 gr SJHP .357 Magnum loading because it usually displays a good bit of fragmentation. There seems to be an obsession these days with 100% weight retention but most forget why fragmentation was considered undesirable to begin with. In most common service calibers, significant fragmentation reduces bullet weight, and therefore momentum, so much that penetration is reduced to undesirable levels. Also, weight retention is very important when penetrating intermediate barriers like drywall, plywood, steel, and auto glass. The Remington .357 Magnum loading however, drives a heavy enough bullet with a high enough cross-sectional density fast enough to both penetrate adequately and expand well despite its tendency to fragment and, to the private individual, weight retention's impact on intermediate barrier penetration probably isn't all that relevant.