Re: How is this legal?
"There *was* evidence that mobile phones interfered with the pump metering/monitoring systems..."
No there wasn't. A few years ago I was looking at whether we could use a GPRS credit card terminal for taking payments at a private fueling area (yes, before you ask, all legal just on private property). So I researched this issue of using mobile phones in petrol stations to see where the issue lay and how we could mitigate it (for instance by keeping it in a metal box etc).
The only thing I could find was a report that detailed the risk of battery powered devices which may be dropped on the floor at which point the battery detaching from the device could cause a spark and the resulting spark could cause ignition of petrol vapour.
This report seemed to led to a decision by other parties that mobile phones were a possible candidate of this event (nothing to do with the actual transceiver, radio waves etc). Therefore they were banned in a chain of petrol stations. This created a domino effect where other petrol stations banned their use without knowing exactly why, just that mobile phones shouldn't be used. In the end it seems that many myths surround why they aren't allowed (even though most batteries are now fixed in smartphones) but the simple case is there is very little risk of using a mobile phone in a petrol station and none under normal use.