One way to be both honest and not burn bridges is to say "I don't talk behind people's back". So either HR will bring in the parties involved (not likely, but

One way to be both honest and not burn bridges is to say "I don't talk behind people's back". So either HR will bring in the parties involved (not likely, but in case they do, you can get your point across to them directly, probably in a constructive manner), or they won't, which you get to keep your honesty and integrity.