In the areas in the instance where there are the whirlwinds moving about we recently discovered that the Warden skill Briar Shield will reflect damage to the whirlwind when the Warden gets hit and it causes the whirlwind to bug and stop moving around wherever the Warden touched it.
I also know for a fact that some guilds are abusing this and will make the Warden in party, whether it be the tank or a dps, purposely run into all the whirlwinds while the healer simply spams heals on them in the process.
I believe doing this is purposefully exploiting a bug and felt the need to report it.