Sold an item on eBay, worried I am going to run into some issues

GadgetGuru

In essence, he wants to use them while on holiday, and then return them when he comes back as he wont need them any more. 
As suggested above, contact eBay by phone. 

As noted in my original message above, there is no need for him to return them as they can be reset using the button on the rear.

He's clearly trying it on. 

If he returns and opens a case, then refer eBay back to his original messages, including the one stating he couldn't open a case prior to his holiday.