The merchant commiting fraud is never a problem because they will always be caught. All you need to do is to do a little data mining and work out where all the cards that have been fraudulantly used have previously been used (the banks share this information). Ross was pretty specific (in that Watchdog programme) that merchants would be targeted. Again, he failed to suggest how someone would be able to run a fake marchant site and not be caught out when banks realised that fraud victims hadn't been charged for a meal out/a book they purchased etc. all at the same location.
The issues in petrol stations are due to crims coming in and pretending to be workers (or actually being workers) and installing pinhole cameras etc. and scanning magstripes. Not a chip and pin problem because the cards tended to be cloned and used in non chip and pin countries.
I'm not sure that I buy the banks using C&P to blame customers because of the two people that I know who have had cards fraudulantly used, one had his cloned at a petrol station and the bank were fine about it, returning the money pretty quickly. The other had his wallet nicked, admitted to the bank that the pin was written down in it, they didn't give him any money back but he shouts about it all the time like it's the bank in the wrong. (Same bank in both cases).