Thanks for everyone's helpful advice. I didn't produce it at the time because I'd put it in my bag and it ended up between the pages of a book I was reading. It wasn't until I got off the luas and removed everything from my bag that I found it. ...
i still dont understand why you did not just show the ticket when asked,i travel on the luas i have the ticket in my hand or in my pocket,its not the sort of thing you buy and then throw away before you get on the tram.
Hope that explains why the OP didn't show the ticket legalrights.