Question about Roman’s big scene

I don’t really have any knowledge on business legality or deals, so when Mattson tells Roman, “You just fucked yourself” I didn’t quite know what he meant.

Did Roman’s outburst put him in potential legal trouble that Mattson can leverage against him, or was he saying that because “Roman fucking himself” was Mattson overpaying for the company, and now he can push Roman out?

When he first said it, I assumed Roman unexpectedly put his foot in his mouth.