There's no rule against using another person's LL so that CM was just being nosy

. Thankfully they couldn't stop anyone even if they did care.
And yeah. It's a paid for service. Exactly. Doesn't matter who uses it.
It also does highlight why tickets/passes should only be shared with people you trust, though. There's a post in a FB group right now asking how to remove their pass from another person's account. That other person can see when they have reservations, make reservations for them, and cancel said reservations for them. They would also have access to any LLs the person made.
The eyebrow you got might have just been wondering if you had permission to use the other person's LL rather than just using someone else's being wrong in their mind if that makes sense.