I used crowbars all the time, and I never break things with them. RL, I mean. My use with them here is limited, because... well, they broke things. And I get just as good bashing without one.
There is always a crack, or you end up making one. You stick the crowbar against the crack, little pointy end. The other end, you hammer. In the event you actually have something that's SO flush there's no grip (and let's not forget most of that technology to make something that damned perfect doesn't exist in a D&D world short of magic), you put it against the place the two lips meet, and you hammer the other end of the bar. It chips the crack, creates a wedge. You jam another crowbar in the opposite direction, push up and pull down. If you really want to crack something open, you stick an actual wedge against it once you get any gap at all, and you hammer that. Push, and pull. You don't swing a crowbar. Levering is actually quite gentle. The only violent part is getting the action end into the gap, and even then the only shock anything inside the chest takes is when the chest itself has to move and stop. Stick something on the other side of the chest, and the chest itself becomes its own reenforcer.
Maybe a glass bottle would break during all that. But a weapon? A piece of armor (which itself gets smacked around all the time sustaining direct contact, and never breaks)? They're not going to break. Given the fact a crowbar only adds... what, 5 points?... to the roll, and weighs a godawful amount (a bit more more than any actual crowbar, except one of the really big "trucker" bars) there should be some advantage to using one to "bash" a chest, mainly that you're not breaking everything inside while using it.
But, this post was more about the badgers breaking items just by smacking a chest with it's snout. I just threw in the crowbar thing because, overall, the chance to break an item seems awful high.
Especially if one hit from a badger is doing it.