The programmers deliberately provided a way to short circuit the displays and get out more quickly, and they did it by replicating code for some features. Bribe is one, but they didn't replicate enough of it. Notably, they left out a test that determines if the battle should be exempt from bribery (and maybe escape in general). The simplest fix is just to break the "short circuit" code, so that it's impossible to bribe without letting the displays run their course. Unfortunately, adding the required operations to make the short path operate properly will take some doing.
Fix Bribery Glitch (must let displays run for Bribe to work)
Edit: OK, I've got a better fix, but I had to reorganize a bunch of code to wedge it in. This bug is kind of meaningless, really, but mystery solved, I guess.