Guess that would be me. I am in a couple of side games (don't think super highly of them, but they have a sort of relaxing quality) so I can play. I also went out of my way to become involved in those games just so I could play. I needed a break in my normal game and running, so I talked one of my players into doing a 4 session thing.
How did it happen? 3 years ago a 2nd edition game started with someone else running. He ran for about a year and a half (some of that a RTTOEE 3ed game). At times he would be busy with work, or looking for work and I would fill in as DM. Once switching to 3E he didn't really seem to take to the new system as well, and it became a problem more with him running, then playing. We also had a few problems in RTTOEE. I would rather DM then not play at all. And I like my Wednesday night crew, so better to run, then not play, Right?