4608 casts for 1 skillup!

Were you at the max (315) for your level until you dinged?
 
Did your toon have gear on ? It is an understatement to say that gear speeds up the skill casting and swimming.
 
Yes had gear on and no didn't ding, 320 was max for my lvl. I was in a remote zone skilling up.

Just crazy bad luck I think. Couldn't imagine doing that by hand!
 
Makes no sense but I swear skillups can get "stuck" sometimes. Maybe the RNG starts churning out the same result over and over. I've definitely had ridiculously long streaks of failure. But THIS is certainly of the Olympic record-setting class!
 
I would just attribute it to that 1 in 1,000,000 chance that you get a bad streak. It certainly is interesting to have logged though.