Technically its not from Humble Bundle, and from the Steam Store Bundle.

You said "gifting HB is against SG rules" which is blatantly untrue without the specification that the bundle has been split. Even if you did specify, we're treading into murky water. Giving away a 4 game bundle key represented as a single game may break the "Do not misrepresent the title being given away" rule, however, I would argue that this is incorrect. I have seen many giveaways that state "if you win this giveaway, I will also give you the DLC to this game." Is this also misrepresenting the giveaway because you get extras? In my interpretation of the rules, this rules is there to prevent guest passes, beta keys, etc masquerading as the real games.

How about Dustforce giveaways? That is a split bundle key but it is certainly not "misrepresenting" anything. Now I know the argument that you will give is that HiB does not allow transferring of keys. HOWEVER, nowhere in the rules does it state that you may not give away the keys. I read through the relevant threads in full when they were first posted, and I do know CG stated that we should "review that bundle's terms of service to ensure you have permission to do so." This is NOT an explicit statement that such giveaways are not allowed. In fact, the first statement of the paragraph "There's no longer a restriction on what games can be given away, assuming they're not guest passes or beta keys" should completely squash any kind of argument you have.

At any rate, the entire point of the contributor system overhaul was so that these kinds of giveaways could be created.

You've been a member for 9 months, you should know the rules or at least know that some rules are not set in stone and are open for debate.