I've killed a decent number of deer with my bow. More than I would have liked, have encountered bone other that rib. Using a quality broadhead helps in getting the job done in spite of a marginal hit. It is of my experience and opinion that hitting the flat "paddle" of the shoulder should not cause damage to the broadhead. Hitting the ridge or solid part of the shoulder bone may cause some head damage, I guess it depends on the angle of hit. Hitting spine usually damages the broadhead for further use at game, however I have still been able to use some in practice.

My setups have usually been on the higher poundage, heavier arrow type using a sturdy 125 gr fixed head(90% of the time that being thunderheads). I don't think its reasonable to assume a head will bust thru bone if not driven to the proper energy levels. As well, I think a quality head pushed fast enough should withstand hitting bone enough to finish its job of killing the animal in a recoverable distance. It may not be usable again, but if it kills the animal it worked.

This is what I expect out of a broadhead, BUT should the unfortunate situation arise where I hit a deer where I shouldn't and don't recover it, I will not be blaming the broadhead.