For my solution, I just disabled the capsule collider in the Die() method. As I felt this was the simplest solution to what the problem being shown was, which was we cant sometimes click on an enemy behind a dead one.
The solution that was explained seems Really overly complex (from my point of view) for what was asked for the challenge and implied by the instructor. So is there a reason why the instructors chose the method they displayed ? Does it tie in for a future feature ?
if so it might be worth, being more specific about what you want from the challenge. As I bet 90% of the students initially just disabled the capsule collider.
Cheers
Paul