It isn't the clutch hub that broke, but the Clutch carrier plate. They break and do not make any noise at all. My bike would creep and a light in first gear and the night before I tore it down to reassure myself that is what it was, I held the front brake and put power to the cltch and started to disengage the lever as to start to power brake the bike. I didn't allow it to break the tire loose but put as much stress on th clutch as I could without pushing the front tire. When I stopped and pulled the clutch in, I had to hit the stop button real fast bcause the bike wanted to keep moving pretty hard after I pulled the clutch in.
With the broken carrier the clutch pushrod can not disengage the clutch pack because the pressure from the pushrod on the pressure plate just shoves the broken part back and keeps the pack somewhat under a load.
I am pretty sure the broken carrier is your problem.
Mine is tore down as I speek because of aluminum shavings in the primary that I am working on finding the source of.
Wonder how long until BDM does an actual recall on 2005 bikes for this issue.
They will all break sooner or later