Did his post count go up too?
Yes
Did this happen in various topics the double posts?
Yes
And the 300 posts are they in a time frame? (same time)?
Within a few seconds of each other - not the exact same time.
Actually, after re-examining things - it looks like there are about 1 post/second. i.e. around 60 posts at 2.59pm then another 60 at 3pm then sixty more at 3.01 etc etc
Is there any flood control settings to that user?
Interesting you should mention that. I forgot it could be set outside of a global basis - I'll have to look into that.
Please... keep thinking out loud