One (okay, several) mistakes I've made in inspecting comb in a TBH:
I would lift the top bar, and forcefully drop the bar back on the hive to drop the bees off the comb so I could see it better. This works, but I have lost the comb too!! You'd think I'd learn after the first one.
The broken comb was usually with honey. I guess honey weighs more and the comb is more fragile (new, fresh comb).
Just an FYI for you....