In a Google Hangout with John Mueller earlier this month on Google+, John explained how it works when a thread in the help forums gets escalated to a Googler.

John said that one of the more active non Google people in the Google forums will see it and they have a way of escalating it higher, to a Googler. John said:

He said this around the 42:27 mark into the video, first explaining how to safely post questions and then how things get escalated.

Here is the video embed:

Forum discussion at Google+.