Bullet/agent perdormance
It should be noted that Platt took a round early in the fight from a distance of 47 yards, if memory serves me correctly. That round, a 9mm Win Silvertip, penetrated Platt's arm, entered his chest and stopped just short of his heart. Had that bullet penetrated just a bit more, the outcome would have been very different.
We lose sight of the fact that the essential elements to winning a gun battle, in order of importance are: mindset, judgment, tactics, marksmanship and firearm. Regrettably, and I hate to second guess LEOs, that two agents died and several more wounded is evidence enough the FBI was not prepared for this gunbattle. All the elements were lackingto varying degrees.
But, as the FBI is our nation's premier law enforcement agency, They studied and demanded better bullet performance and they got it. We all benefit from having available premium self defense bullets that didn't exist prior to 1986.