The PAAB code applies to advertising materials. The code does not cover questions asked during a live exchange of medical information. Nonetheless, it would appear prudent to instruct your commercial employees not to ask public questions (or provide answers) during sessions involving scientific exchanges of information in order to avoid the perception of promotion. The speaker could be trained to respond with something along the lines of “Because drug X is not indicated for condition Y” if a commercial employee from another manufacturer where to ask this question.
I can’t imagine an issue if the employee asks the question privately after the session (i.e. one-on-one between employee and speaker).