Reads like bullshit anyway. Something went wrong, he throws up the "it wasn't me it must be those evil hackers" defence rather than accepting the blame for putting his device together poorly or letting it go out of range. There would be no way of knowing for sure if another device took control during the incident (because who would build that in to a home made UAV), so he *may* be telling the truth, but if it happened twice in one day either someone is out there deliberately hashing the channels to mess with everybody, or he just went out of range/did something wrong/etc.
nah I doubt he is telling the truth, many are designed to lose signal and be ok hence they will hover and wait for signal or some come back to you and land (within 20ft radius or whatever for many hence you DON'T launch it from a position with trees around). Also I know a couple of drone flyers where I live and they tend to know all the others in the community who fly, what models they have and tweaks to them even and this is a large city!
So the hacked thing is crap and if someone did do so earlier in the day he'd likely know the person responsible if they were in range with a low power device to do so. He just needs to cowboy the fuck up and admit his mistake.