I think that by reversing their call, the AMA has decided that justice should be handled on the track(like it has been in the past).
The fact is if I had been in DV's shoes, I would have been upset. And if the sanctioning body had penalized the offending rider, that would have satisfied me. But then if they decided to lift the penalty, I would have have no choice but to set things right personally, on the track. That's the way it's worked since the beginning, both locally and nationally. And apparently the AMA has decided that there is no reason to change anything.
NASCAR worked the same way for a long time, but as it became increasingly popular and corporate america began to take notice, things had to change. NASCAR's governing body was forced to take a more hands-on approach to discipline. Drivers couldn't be allowed free reign to settle differences on the track, it was bad for the sponsors which is bad for business.
Currently, MX/SX is still a bit of a fringe sport, but popularity is increasing and it may soon be a big-time, big-money sport as well. At some point the AMA is going to have to act like a governing body, instead of just being a figure-head/promoter.
Having said all this I'm actually a big fan of the current system of checks and balances. --A rider takes another rider out. The other rider takes him out in the next moto. Justice is served and the slate is clean. The end.-- But at some point things will have to change.
CJ
P.S.- With all due respect to MrMXer, I have to disagree. In order to accomplish a block pass you must brake late and beat your oppenent to the apex of the turn, getting in front of him and taking away his momentum. Broadsiding someone is generally not considered a block pass, at least not where I'm from. And yes, there are numerous things DV could have done to avoid getting taken out, the most sure-fire of which was to not even get on the track in the first place. ;)