Subterfuge + Ambush x2

Hello all.

First, I have been playing MoP for like a week, after playing for like 4 months on TBC Expansion. Before that I have no knowledge of WoW. So expect noob questions.

Anyway, just wanted to check something regarding the Subterfuge talent.

Subterfuge: causes Stealth to break 3 seconds after dealing or receiving damage (rather than instantly, without the talent).

Now, my question is this. Given that right now if I spam Ambush for a second time It will trigger since I'm technically still in Stealth.

The problem coms when break Stealth, I can't seem to attack the monster normally. Only by using spells and abilities such as Hemorrhage to get more Combo Points thus allowing me to kill the target. Otherwise I'll just stand there getting my butt handed to me.

Now, I'm not sure if it is a Bug or what, or if it is normal for that to happen.

TL;DR: After using Ambush x2, thanks to Subterfuge talent I can't attack the target normally after breaking out of Stealth. Bug or not?