Father's Day - S3.E14

Due to frustration at being unable to wrest custody of his son from his drug addicted wife, Corporal Wetzel was distracted during a war game exercise and crashed a tank. Accused of dereliction of duty, Wetzel admits to being diverted on the job, but insists that Mac and Harm must keep him out of jail, since his arrest would certainly mean losing his son.

Harm and Mac like Wetzel and understand that his frustration accounts for his poor judgment. But nobody's more surprised than they when Wetzel winds up in a tank in a stand-off with the military, questioning why he's being forced to choose between being a marine and being a father.