There seems to be a glut of reports from all over the UK, but we have Tesco stations here in Ireland and there's been no issue - assume the same source? It seems to be eminating from a particular storage area in SE England only.
As for other types of fuel, if people cut corners then yes, the possibility is there. However, the regulation is fairly tight, (indeed, regulated by the same EU that most people on here rail against), but is really only as good as the people operating the monitoring systems. This seems to be the weak point of any business system.