Hmmm, I see. I did not know that dyingdreams. Thanks a lot for telling me. Let's just hope that he is legit (and he really does seem that way, because he never rushed me or behaved strangely).
And therein lies the problem; everything could seem fine and you could play the game without issue for months, and then one day Steam will magically remove it from your account. The way I see it, this is a shortcoming of the Steam Gift system, and something that they desperately need to address, however they probably wont since the issue is likely limited to a very small number of people (most of which won't even try to argue with Steam about it) and if anything it discourages 3rd party sales and encourages purchasing games directly from Steam.