They can get fined for being ejected.
But, Polk didn't really leave work per se. He just left the third base coaches box. He is technically still in charge of the team, and if he tells Raffo to go coach there, that's his call whatever the reason.
Now, I'll tell you what makes me mad about this situation. The reason real reason he left the coaches box is so that people would say, "Gee isn't that a shame that those USM fans are so mean and bad that they forced a living legend into the dugout in his last game ever there." I guarantee you that's what's going through his head right now.