Him, sir? Nossir, must've tripped

Rico says his father sends along this charming Christmas story:

The Best Buy sales manager at the Augusta, Georgia store, Orvin Smith, told The Augusta Chronicle that a man was seen on surveillance cameras putting a laptop under his jacket.
When confronted, the man became irate, knocked down an employee, pulled a knife, and ran toward the door.
Outside were four Marines collecting toys for the Marine Corps' "Toys For Tots" program. Smith said the Marines stopped the man, but he stabbed one of them, Corporal Phillip Duggan, in the back. The cut did not appear to be severe.
The suspect was transported to the local hospital with two broken arms, a broken leg, possible broken ribs, and assorted lacerations and bruises he obtained when he 'fell', trying to run, after stabbing the Marine. The suspect, whose name was not released, was held until police arrived. The Richmond County Sheriff's office said it is investigating.

Rico says the investigation will, undoubtedly, determine that, even four against one, it was self-defense...