I thought it was confirmed that we would be able to choose which character would be choosing the dialog options and performing skill checks in the cinematics after one is triggered. There is a button in the bottom left that allows you to switch character, but that only allows you to exit the cinematic and move them around.
Likewise it'd be great to be able to switch with your friends and deciding who's going to be doing the talking on the go rather than having to roll with whatever is randomly triggered.