The "35min" block you are referring to took 17 minutes and 3 seconds btw 
While most blocks (over 98%) are spot on within the 61 sec window 
While most blocks (over 98%) are spot on within the 61 sec window which block was this?
Well, the only block that took more than a couple of minutes around the time of Georges post was: [252698]
That one took 17:03 minutes