Sean,
at this point and if it was me I wouldn’t worry about this, the worst that can happen is he sends it back to you undamaged and you issue a refund.
in all probabilities like you said he figured how to turn it on.
to those who say don’t sell overseas, I humbly disagree. I sold many expensive photo equipments on ebay and the buyers were from all over the world: Hong Kong, Germany, France, Switzerland, Australia etc.
never had a problem but one from Taiwan who said he didn’t receive a $450 filter I sent via USPS with proof of shipping and insured, but they didn’t provide online tracking, as he didn’t want to pay for fedex because "it was expensive"... Postal service said they checked with their counterparts in Taiwan and they informed that it was delivered but couldn’t provide proof... That was good enough for the post office to deny my insurance claim but not for paypal & ebay to rule against me.
So I learned my lesson to cover myself all the way, only send it with the likes of fedex, UPS, DHL etc. where they provide online tracking & fully insured with informing the buyer in the ad that customs delays or expenses are their responsibility... If they don’t wanna pay for those services then they can buy their stuff elsewhere. Never had a problem again.
like I said I wouldn’t worry about this until The buyer responds.
Good luck and Happy Holidays