As an Irish man I can tell you us Irish hate using cards in pubs we always use cash its a cultural thing, Ive been in many countries and it doesnt matter if its at home, Australia, Canada or Glasgow us Irish male and female young and old hate using plastic in bars and pubs, ask any Irish person. I am sure Karen was no different.
This is from a few pages back but can I say I've never even heard anyone say this before about irish people! I'm Irish myself, (I live in Glasgow hence my keen interest in this case) and I always use my cards instead of cash because it means I can keep track of all my spending using online banking and I feel I'm more likely to get robbed/lose money carrying around wads of cash. It might be the way some people are brought up to use cash but it certainly isn't a cultural thing.
As for people wondering how the police found out he bought a barrel, the first thing the police would do when they traced AP was get his phone records which would show that he drove to a B&Q on the sunday.