I bet the reason the Chimera's Froststorm Breath is "inconsistent" with the tooltip is because they changed how it worked.

Like posted above, people found out you could grief with it. If you did a faction-change (and they were given out free all the time on the PTR) you could use a Chimera to attack your own faction. Tons of jackasses stood around cities and griefed everyone. The attack was OP. It 3-shot everything.

Some people reported in Orgrimmar you couldn't even load in before you were dead. Dozens and dozens of Hunters running around killing people.

There was a defense. The attack is considered an aura, so you could use a /cancelaura Froststorm Breath macro to stop it. Some places you had to mash it non-stop to survive.

I am thoroughly of the opinion the people who did it to grief should be banned from the PTR. They shut down some of the cities and testing by griefing non-stop. They would stand by the test dummies and keep attacking people. Without the macro you couldn't survive. These things did insane damage.