The troll fired FBI director Comey, supposedly for treating Clinton unfairly in July by announcing that Clinton would not be prosecuted.

This was said to exceed his authority and thus do wrong to the Attorney General at the time (who did not, however, object).

If the cheater really wanted to fire Comey for this reason, he would not have waited until now. His real reason must be something else. Many suspect it's an attempt to stop the FBI from investigating the cheater's team's relations with Russia.