Steve Austin and Vinnie Jones would often play jokes on each other during filming. Steve would put inflatable sex dolls in Vinnie's trailer and also put up 50 signed autograph pictures of himself all around his trailer.
Steve Austin was originally offered the part Vinnie Jones plays, but after WWE decided to make the movie in their WWE Films department, they gave Steve Austin the lead role.
Steve Austin referred to Vinnie Jones as #2. Vinnie Jones referred to Steve Austin as #1. The reason they referred to each other this way was how they were billed in the film.
Plane in background for fight sequence is B25 from WW2
When Vinnie Jones takes the machine gun from the cameraman he says "Merry Christmas". This is a reference to Die Hard. The gun is the same type of gun as John McClane obtains before famously sending the message "Ho ho ho now I have a machine gun". Ho ho ho. Like Santa. Christmas.