We didn't expect the decision to have such serious/enormous/tremendous 'repercussions'. [='consequences']
We did not consider the possible 'repercussions' of our actions.
(..) I can hang out. You can show me around. That is out of the question. You must not leave this house. You must not see or talk to anybody. Anything you do can have repercussions on future events. Do you understand? Yeah. Sure. Okay. Marty... ...have you interacted with anybody else today besides me? (..)1985 Back to the Future