A victory of stereotypes over common sense?

According to the AP:

Kelly said officers were on the way to a Pennsylvania town to talk to a tourist who might have recorded the suspect on his video camera. The video shows a white man in his 40s taking off one shirt, revealing another underneath.

The commissioner said there's no evidence that a Pakistani Taliban videotaped claim to the failed car bombing is valid.

Earlier, there had been reports Pakistani Taliban claimed responsibility for the failed NYC bomb attack.

I am a little curious about the The video shows a white man in his 40s taking off one shirt part.

I wonder if this is a little bit of a case of stereotypes of Arabs and Muslims in general winning over common sense.

I mean, how can the fact that the video shows a white man indicate anything —one way or another— about a Taliban or Al-Qaeda connection?