It's for now about impossible to plug hibernate validators in an osgi environment with extenders like spring-dm.
I've found multiple blog entries explaining the bootstrapping issue of validation api.
I'm not an OSGI expert, so I think you'll better understand the problem than me.
The problem remains that validation api is not usable in a valuable osgi environment for now (spring-dm, blueprint...).
Thank you to investigate on this problem, I give you a sample project in order to test it ('mvn paxrovision -Dframework=equinox' in order to run the server).