Bad design isn't a bug if it's working as intended.
Not according to the professional quality assurance teacher I had!
I've been informed that even if they let it go it is still a bug if it can be considered a bug. (Same person informed me Design Flaws are definitely bugs)
I agree the cutscene where the last bandit appears could be handled differently. It truly breaks the flow if you're sneaking around looting the bodies, then suddenly one more bandit appears and pulls you out of stealth with his magical powers of dialog initiation But it didn't feel like much of a problem. They must have had the bomb ready for situations like that.
If you break it down that's basically my only complaint- the only real other thing is that I'm not sure what the dev's intention for what the player is supposed to go through upon disarming the bomb is.