The browser are not hacked all at once but one at a time with Safari being the first on the schedule. This is true in past pwn2own contests (including last year) as well.
I understand that. I understand that people are using "ZMG SAFARI FIRST TO DIEEEEEEEEE" headlines to get traffic, but people are falling left and right for this flamebait. If they all went at the same exact time and Safari was the last to get owned after 8 seconds, does that somehow make Safari more secure? Of course not.
Maybe people should stop taking the bait and just admit that Apple needs to focus more on security and this is further proof of that.