Weird man.

You shoulda used some axe or some shit, even if you did smoke outside the smell can still get on your clothes.

They could have thought they smelled it too. I've had my parents claim to smell weed when there wasn't any smell, they could have just gotten lucky with their guess.

My dad also said he smelled beer in my room like 3 nights in a row, and I've NEVER had beer in my room (vodka once, a LONG time ago) and he honestly thought I was getting drunk and drinking beer in my room.