In any case, I am glad that you are OK, mathman. That is the matter of REAL importance here.
As you said, it probably was an overcharged round that caused the "sticky bolt". You say that you didn't "beat up" the bolt...to get it open - OK, I'll take your word for it. To be fair, it certainly IS possible that the bolt handle happened to be defective....because the solder joint should have let go, well before the handle simply broke. But, the handle (a cast part) may have had a hairline crack in ....commonly referred to as a casting occlusion. If the bolt functions fine....slides back and forth in the receiver, locks and unlocks without binding, etc.....then it APPEARS that there is no permanent damage to the receiver or locking lugs. I would examine the bolt body and the lugs VERY closely, though, to be sure. Perhaps Remington will repair the bolt handle (replace it, actually) on warranty. I hope that they do.
But, I wouldn't simply condemn the rifle. We milsurp Mauser people are very used to "sticky bolt". Fortunately, in the case of the Mausers, the bolt handle is welded on - as part of the bolt body - and very robust. That is a weakness in the Remington bolt design, to be sure. It is not necessarily true that milsurp (7.62 NATO) ammo should not be used in the 700. I've had two rifles, exactly like yours (700 ADL's -in .308)...and together, both have seen a couple of thousand rounds of milsurp ammo. I always used the Australian ADI ammo, or, failing that, the South African ammo. Never had one problem with either....or the rifles...and both were quite accurate in my rifles (with the Aussie having a slight edge). Probably, the majority of the Santa Barbara ammo is OK. The combination of case dimensions that are perhaps, at the maximum limit of the spec'd tolerances...and the over- hot load, are what directly caused this problem. I would also examine the cartridge case in question closely, because I believe that there must be some signs of over-pressure (if not incipient case failure...then a cratered primer, embossed bolt face (on the head of the case), etc.). As to what to do with the rest of the Santa Barbara ammo...I don't believe that I would shoot it, until you are sure that the remainder of rounds are safe (an obvious suggestion, which I know that you've already thought of). If you handload, or have a friend that does, you could pull some bullets, then weigh some of the charges. This will give a good idea of the variances, if enough charges are weighed. Reject the high and low extremes (especially the high)...and average the rest....then reload the cartridges. It might be wise to back down the charge weight by a grain or so. Then, you would have ammo that you could be pretty sure is safe to shoot in the rifle. Of course, if you are not a handloader, this suggestion is moot.
Another possibility, which is NOT scientific...and NOT entirely reliable... is to shake each cartridge, listening carefully for variantions in the sound and feel. This will ONLY work in a very quiet place....and IF you have a good ear and sensitive touch. It will NOT allow the charges to be matched - and certainly will NOT allow variations in charge weights of less than several grains to be detected, but it could aid in "spotting" any more over-loaded cartridges. The real danger is that, if the first few rounds you shake are over-loaded....then the standard for detecting overloaded ones will be off. Whatever you do, be VERY careful.
Anyway, just a few thoughts. Good luck with this....and be careful.