Revealing mistake: When Bill Murray is blowing up the prison door, you see the explosion, but the explosive is still intact.
Revealing mistake: When Bill Murray and Harold Ramis are whipped into the rope snare traps there are huge gaps in the ropes between Harold Ramis' feet that would make it impossible for the trap to secure him.
Revealing mistake: The couple make love in the General's bedroom in the US. Later they make love in a German hotel room. The same set is used for both scenes.
Chosen answer: According to the movie's premise and plot, once they (the platoon) impressed the brass at graduation and was assigned to the Germany gig with the "EM-50", Sgt. Hulka would naturally be with them as he was their original commanding officer. Plus, it would be logical to suggest that he would personally assign himself the detail of overseeing his platoon as they were his to begin with.
CCARNI ★
He's assigned as a Drill Sergeant, that is his job. Once he was fully healed he would have been assigned another group of recruits.