The point is that the last pick expired at 11:58:38 PM EDT, which is before midnight. That means that he's meat should be allowed to make the next selection. He can choose to wait for bigmahon or make his selection anytime up until just before 1 PM EDT tomorrow. As soon as he picks, though, the next guy in line (the splinter) is also free to choose.
The time for bigmahon in Round 5 was 8:58:38 PM EDT to 11:58:38 PM EDT. That time is up.