Geb didn't duck Wanjiru. The're saying he blocked him.
Making it prohibitively expensive to include Wanjiru in the race that he was already signed up for.
Geb now runs for money not titles. He has more earning power as the reigning record holder. Losing his record and losing races diminish his earning power. Wanjiru more than anyone poses a threat to him.
Geb had all of the incentive to stipulate conditions based on who was entered in the race.
Wanjiru stated that he wanted to race Berlin.
Now we can all draw conclusions to why he didn't race.
The anti conspiracy people say that Berlin just didn't come up with enough money to get Wanjiru to play.
Others think that in some matter Geb's team had a role in Wanjiru not running Berlin.
We know they didn't race and fear they will never race.