[Dumb question] Does it take time for another steam user to see your newly activated game?

Here's the thing, my GA's winner had recently won, but didn't activate a game. He explained the situation to me and I gave him a chance to activate it. The strange thing is, that when he said he did, steam didn't show me the game in his account. Naturally, the first thing that crossed my mind was that he's using sgtools's down time for his advantage, hoping I won't check manually. Now everything is OK, but I can't stand that I looked like a douche for somewhat accusing him for a liar. So, tl; dr:
What's the chance this was a software mistake and I made a fool of myself?

Also, I can't sleep, thats why I'm asking stupid questions. Please have a gib.