First, per a league source, the other "area on way to field" is a bathroom. The bathroom consists of one toilet and one sink and a door that locks from the inside.
Second, according to the same source, the person carried two bags of balls into the bathroom: the 12 balls to be used by the Patriots and the 12 balls to be used by the Colts.
Third, from the same source, the evidence comes from a surveillance video that was discovered by the Patriots and given to the NFL early in the investigation.
Fourth, again from the same source, the video shows the employee in the bathroom for approximately 90 seconds.
So this video was actually of the Patriots staffer going to the bathroom for 90 seconds- clearly not enough time to perfectly deflate 12 footballs- and the footage was submitted by the Patriots themselves.
The whole argument is grasping as straws at this point. Now it's just funny.