The 'Invincibles' saw their 49-game streak come to a halt against Manchester United at Old Trafford.
The 'Invincibles' had gone a whole league campaign unbeaten and came to Old Trafford in the hope that that run could continue for a second season running.
But Sir Alex Ferguson's side had other ideas and duly beat the Gunners 2-0 in a controversial clash.
Not without a Rooney dive to win that initial penalty, though, according to Keown.
During a Tackle Keown session on the Daily Mail's website, the 48-year-old was asked if '50 not out' T-shirts were printed ahead of the Man United clash.
He replied: "I've absolutely no idea! I wasn’t at the club by that point but I’d be very surprised if that had been done. I doubt very much if Wenger would allow it. You can’t stop fans from doing it.
"It was interesting that Wayne Rooney stopped us from going unbeaten with Everton and then also dived to win a penalty and stop us from keeping the run going."