Dude I just checked out that throne on the web site. The legs on it are not made for centrifugal balance. I'm also an architect and I think that Sound Percussion makes a much better throne than that one. I use one and my older son is 6'2" and almost 260lbs. Never had an incident like that.
You need a spread leg type of throne to beep your balance. The one I saw on the site looks more like a bar stool type of layout. Any one can get injured on one of those.
Have you checked out
Gibraltar thrones? Don't waste your money and the next time you go to a drum shop, squat on the sucker and spin a little before purchasing anything. I'm just glad you didn't get hurt brother.