but I am sure this can be resolved with the support team, as the gift sender is using shady practises, not the receiver.

If you mark Received on a title and it isn't in your library, and there isn't a large-scale issue that staff is aware of, they're still likely going to flag you for Non-Activation. Regardless of what the GA creator does, it's considered to be the winner's responsability to ensure that they have a working copy of the game, and that they keep staff informed of any changes [either by leaving comments on the GA itself, which also has the benefit of informing the GA creator, or by contacting staff directly].

Obviously, staff'll be sympathetic to mitigating circumstances [such as a surprise revokation or the title showing up in library and running properly, but not being showing as owned], but that doesn't necessarily mean they'll be aware of those circumstances if you don't tell them about them, nor that they'll confirm with you beforehand what the circumstances are, or cancel any granted suspension in a timely manner.

As I note below, winners do have the means to confirm these things on their own so, regardless of staff's understanding or not, it's still something staff isn't going to take extra steps on for each occasion, just to first confirm that there wasn't an unusual circumstance. We can determine that they're just going to assume a normal Non-Activation by default, regardless of where their sympathies lie or who site rules inherently favor, as it'd otherwise require them to put in n unnecessary amount of effort for a rare occurance that winners can manage on their own to begin with.

In short, regardless of whose "fault" it is, the winner still should do their best to "cover their ass" in these matters.
Naturally, the GA creator'll be punished either way, but winners should still be careful to not get themselves dragged into the matter.

okay