Jess's mind was made up to jump from the get-go (Faith character) but Eric was trying to stop her. If he hadn't tried to stop her, she would've jumped on her own.
If her glove didn't come off, Eric would definitely NOT have followed. I'm not sure about Devin -- he wanted to jump, but was afraid, until Jess's glove came off. Then the need to save her overrode everything, even for Eric.
I think you're right that the deliberation gets them nowhere, because Jess would've jumped with or without the deliberation, and Devin & Eric only jumped because of the glove.
There are also some background/minor characters who jump and some who don't jump, but I realize now that I didn't show any deliberation at all for them.
Finally, in the next scene there is one other character who jumps after them. He also only jumped because of Jess's glove coming off, though it turns out he's too late to help her.