I read a post about "The Vault" on another forum that complained about how one member of the team clicked through dialogue before another player (who had different options for responding) had any opportunity to respond.
I've heard similar complaints with branching dialogue and optional objectives in regard to other missions.
While it is true that a team should take a disciplined approach to completing a mission cooperatively, it is also true that team mates may not realize there are any other options because they can't see them.
It would be useful if the game was able to recognize all of the responses available to each team member and put up ALL of the buttons for every player... however, a response can only be clicked by a team member for whom that choice is valid.
Allow me to illustrate with an example.
You have a team with 1 Science Officer, 1 Engineering Officer, and 1 Tactical Officer. The Science Officer also happens to be an Ambassador.
The mission has branching dialogue for each of the classes, plus a diplomatic option.
In one dialogue box, the Engineering Officer sees all of the responses for Science, Engineer, Tactical, and Diplomatic as well as a generic response. However, the only responses he can actually 'click' are the Engineer and generic responses. The rest are greyed out for him, but at least he can see that there is a Diplomatic option and that would give the team a chance to decide which option they should try.
My apologies if someone else has already suggested something along similar lines.