I know I can flag one of the relevant posts as "Other" as explain to moderator but before doing this prefer to get some fresh sets of eyes look into it and prevent embarrassing flag if it's legit.
The two "suspects" are:
They joined in a day difference, which is fine so far.
What raised my suspicion was the bounty of this question - drooooooid started the bounty 2 days ago then suddenly today posted answer of his own. Nothing suspicious so far. However, 10 minutes later Mr. "vote-up-and-accept" posted another answer and after less than a minute the bounty was granted to him by drooooooid. Why didn't he wait for more answers?
Sniffing around some more, I quickly found this question as well - Mr. drooooooid started another bounty (+150 this time) and lo and behold! 2 minutes after the bounty started our famous "vote-up-and-accept" posted answer that was also upvoted instantly.
I guess this time he was waiting before granting the bounty to not raise too much suspicion, but unfortunately for him "vote-up-and-accept" answer got deleted by now by a moderator, guess it's just because it's poor not related to sockpuppeting.
What do you think?