The first round started Dec 21, and ended on the 28th29th. The second round would have ended on Jan 5, which is 7 days later. There were two entries posted on Jan 5, one at 12:34 AM and the other at 9:54 PM.

I didn't see anything in their thread announcing the specific cutoff times for entries. Technically speaking, they could argue the cutoff was before anyone completed their entry.

They also said they would host the giveaway up to 4 times per month
Even though they didn't technically say the giveaway was going to stop, they did not specifically say it will continue, and my reading of the post announcing the giveaway doesn't obligate them to continue additional rounds.

It also says only forum members that are "member" rank or better can participate, although this is listed under "bitcointalk" and could be read as the contest is only open to "members" and better. cornl was the 2nd person to enter and his merit history reflects he only had 2 merit as of when the round was over, but the other person who entered in time, rat03gopoh did have enough merit to rank to member.

The additional requirement is ambiguous, and it is not clear to me what was expected to be eligible. It appears they speak Russian, perhaps as their primary language. I tried translating the additional requirement into Russian and back into English to see if ambiguity is removed, this is the result:
Still not very good.

I don't think how they conducted themselves is very professional, but I would not consider being unprofessional a reason to call the person a scammer.

I am not going to advocate one way or another for or against their tag. Some people have avoided getting tagged for a bigger stretch of logic, but I think that logic was completely BS, however it is precedent -- there is no need to re-litigate that here.