TAG rules would be better if the TAG was considered a Vehicle. (With the notable and not-so-rare exception of unmanned Tags) That would solve some strange situations. For example "You can't ride two vehicles at once!"
Motorcycles are Equipment. TAGs are Troopers that are occasionally treated like Equipment. It does have some weird problems currently.
100% agreed with @macfergusson in this case. If your TAG is still conscious and the pilot dismounts, you're not in LoL. If your Lieutenant is on a motorcycle and dismounts you're not in LoL. But if you start the turn with an unconscious TAG Lieutenant, you're in LoL, whether or not you have a dismounted pilot running around. Dismounting the pilot doesn't make the TAG stop being unconscious. This is why you have rule reminders that you still don't generate an order, etc.