if there was a fire alarm at the end of your restaurant meal

would you leave without paying?

apparently 50 customers in Liverpool just did this

[obligatory Scouser joke here]

I have not done in the past (i.e. I waited) but I might leave if it was taking ages and I had to get somewhere

Apparently they used to trial all anti-fraud devices in Liverpool on the basis that if they couldn't get round them they were fit for a UK rollout e.g. utility meters. 

I wouldn't wait but I would pop back at a later date and pay