It's still possible, especially if she and Coulson get caught against the opposite wall and Bucky has to chose between hitting the button and protecting them.

She doesn't bring it up. If he hasn't already considered it, then they'll make that call in the moment. "Fine."

Sharon looks over at Tony, pacing off to the side. "Remember you'll be bringing in Agents Romanoff and Barton, Stark. You can't just burn in like a missile."