Just for interest sake, what does the surface off alloy looks like after coating is removed?
I spoke to a couple of his customers, and was told that sometimes he gets large orders, and impossible delivery deadlines, and, I suspect he may have rushed things a bit.
As a general observation, if first coat is applied too thick and not dried enough before bake that is most probably is main suspicion for poor adhesion.
Second guess is, that he may have overloaded his oven, and the bullets were not done correctly or received uneven cook.
Possibly it also could be a combination of the two scenarios.
With limiting the speed, he may already knows that they were not perfect.
There is really no reason to limit speeds with the coating, but alloy properties is limiting factor.