Anyway to claw back write access on a shared file?

I have an Excel file shared between several dozen people via a URL - I wanted more flexibility than just using a Form to collect some information.

Someone appears to have opened the file on desktop and now it's read-only for the rest of us. It's out of hours so I can't get in touch with them right now. They're also part-time so it might be a couple of days before I can get hold of them.

Copying the file and re-sharing is going to cause mass confusion. Is there any way as the original creator of the file that I can assert my authority? Would it work to, say, change the sharing permissions and then re-open it? Would that work, would it break the URL for access? Am I just SOL?