It’s a story every lawyer has dealt with. The client pays your retainer (presumably the $375K in this case). The trial starts, you burn through the retainer, and you start sending bills. The client doesn’t pay but keeps promising they will, and you generally can’t back out of representation during a trial unless there are circumstances more extreme than unpaid bills. You can petition the judge to let you back out, but if the trial is underway, it’s not likely to be granted. So the bills pile up. Then when things have slowed down and the bills are way overdue, you tell the client to pay up or you’ll sue. And once you sue, you obviously can’t continue representing the client, so you ask to be released from the representation. As they’ve done here.
But please, keep telling me how my profession works.