Huh? By my count I come up with at least three (Weavers actions that lead to charges and a warrant, the serving of said warrant for his arrest and fnally the stand-off) ...
Lon (right, not Ron) Horiuchi was the sniper and he worked for one particular agency.
It still involved internal affairs, whereas the confrontation at Mt. Carmel involved agencies and military from outside of the United States. Lon didn't have to get permission to shoot from the President.
At Mt. Carmel, the decision to eliminate the Branch Davidians because of the harm they were doing to the President's potential re-election, and his permission, via Janet (shakes) Reno was needed and given.