Double Ninjutsu, glitch or not?

[Magnedeus]

I am currently lvling my Ninja to 60 via potd and i stumbled upon something wierd. I doubt this is supposed to happen, but sometimes when i cast a ninjutsu i end up casting 2 at the exact same time even through you can only do it once every 20 sec. Is this a glitch or am i inputting the mudras too fast?

[Kurando]

Sometimes it happens to be too, it could be down to latency I'm guessing although it only happened when I was on the NA datacentre. I've yet to experience it again on the EU one. Well getting in an extra Ninjutsu ain't all that bad if it costs nothing.

[Zerathor]

It means you've believed it hard enough to become a real ninja. You'll be receiving your orange glamour coat in the mail.

It's just packet loss. You're really only doing it once, but client side you will do the animation twice.