Have to 'Walk Away' from negotiations when you enter the Promises screen and can't just back out of it

This is actually by design. In real life you wouldn't be able to just walk out of the meeting randomly. Hope this helps, thank you.

I've just come in here to report this myself. Surely that's got to be reconsidered? Often, particularly at lower levels, you have no real idea of whether a player wants Fringe or Star player status until you click the contract negotiate button. To then be committed to or locked out of talking to that player again is ridiculous 

I thought this was a bug, I'd change the promise and if the accept press right arrow key to go back, I'd get a popup saying finalise before leaving, say yes and press the left arrow to go back and change the contract

so if I finalise a promise and walk away am I still able to negotiate the contract ?  

Sounding out agents allows you to get a better understanding of what a players expectations would be. However, it is simply the reality that there are times when you'll look to begin discussions with a player and you're just too far apart or you make too many missteps that the agent is no longer willing to negotiate with you. 

If you walk away you wouldn't be able to negotiate a contract because you've walked away from discussions.