Remember, you need the same bikes on the same dyno at the same time.
The '04 R1 could easily have ended up 148rwhp on that dyno at that time.
With my '02 954, the same bike, same "system," same year, same equipment on Dan Kyle's dyno was SAE 149.5rwhp, and then dynoed at about 139rwhp on the Mach 1 dyno near my house. However, it was the strongest 954 dynoed to date, picked up 12rwhp and about 6rwtrq with the full Arata, PCiii and map (back-to-back dynoes comparing stock with no riding in between) (to get ot the listed 139 or so), was neck in neck with a '03 R1 full system and map on that dyno, and down by about 4rwhp and 5rwtrq to a full system and pciii G1k on that dyno. So, each dyno is different.
Information like this dyno of two bikes is why the shootouts are so interesting. So far, all 4 of the liter bikes appear to be grouped at about 150-153rwhp--virtually the same. The Honda, while possibly missing a few ponies in the nosebleed section of the powerband, appears to have more grunt in the middle and a linear, easy to use power curve.
Bottom line, a very interesting time for liter bikes!