Wouldn't it be easier to ask him to check the RR battery to see if thats dead seeing as everyone who's had the RF issue reports flat vehicle battery!
I don't see how the RF problem will prevent another receiver like the AA's tool to test the fob either!
And finally - now he's not using the fob but manually locking / unlocking the car should mean he is still getting vehicle battery drain if he was suffering the RF issue.
Its a real common head ache, I know - but in this case I just can't see it to be true.
But to be sure - you can always go and unplug the antenna behind the panel on the drivers side of the boot - this normally provides a work around for the RF issue rather than going out and spending the £100 on a new unit only to find your key fob is still fooked
I don't see how the RF problem will prevent another receiver like the AA's tool to test the fob either!
And finally - now he's not using the fob but manually locking / unlocking the car should mean he is still getting vehicle battery drain if he was suffering the RF issue.
Its a real common head ache, I know - but in this case I just can't see it to be true.
But to be sure - you can always go and unplug the antenna behind the panel on the drivers side of the boot - this normally provides a work around for the RF issue rather than going out and spending the £100 on a new unit only to find your key fob is still fooked