Part and Parcel

In Germany, there is currently a manhunt happening, because an inmate of one of their prisons managed to escape... by mail.

Apparently this prisoner, convicted of drugs trafficking, hid in a large cartboard box that was then taken away by courier. The courier contacted the police when he noticed the tarpaulin on his truck was flapping in the wind, found that a large hole had been cut into it, and there was an empty box on the floor.

Now let this sink in for a minute because I have some trouble imagining this. It seems like the easiest way to escape (10 points for inventiveness), but how in the world do you manage that? This must have been a pretty sizable box to begin with, unless this man was a contortionist by trade. I get the adressing and stamping beforehand and everything, but how do you close the box after you've stepped into it? My mind's eye keeps seeing this cardboard box with two holes in the sides with two arms sticking out...

But my real concern is for the courier. Imagine having to carry such a box to your van... Ouch!