I don't know if there is collusion or not and I do not want to get in the middle of that. However I have a comment

It has been suggested that the fact that certain players have changed teams back and forth several times means there is collusion. I can't rule it out but its not really proof either.

I present the following scenarios wherein I KNOW there was no conclusion.

A certain team in a certain league has swapped certain players, including Trevor Hoffman and Matt Mantei back and forth a couple times. I know there is no collusion... just one aggressive guy pulling the wool over someone.

In another league I have seen Carlos Lee, Geoff Jenkins, Jose Santiago, Steve Kline change teams like 5 times in the last year... and some of them have been on the same team twice (although in this scenario there are more than 2 teams involved).