To be clear that was Safari on OS X. Now I’m know as OS X has gotten more popular we are hearing more about the hacks, but there have been years it was the first hacked at this contest and all the excuses ensued.
For years, the prize was only the computer on which the target was hacked. . . and every hacker wanted the Mac. Later they increased the prize to the computer plus cash, which grew as the manufacturers and publishers got involved.
The exploits are NOT hacked at the contest but before the contest. . . with months of work. Charlie Miller, the ex-NSA computer expert who won five times in a row said he used his staff of two other ex-NSA guys to find the vulnerabilities and develop an exploit, which would then be weaponized. The script to accomplish the exploit would be handed to the referees for execution on the targeted computer and Voilá, done. . . in seconds. It all came down to who got the first 15 minute window and choice of machine to work on. The winner of the previous year's contest always got first choice. . . and Charlie always picked the Mac when he was targeting a computer. That is the only reason. . . because the rest would fall just as easily for the same reason. Prepared exploits.