"most likely caused" and "surmised" make it sound like speculation. If he was injured inside the van, why were his feet dragging on the way to the van?
"Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude." ~ Thomas Jefferson
the legality of the arrest, (and i believe the arrest to violate several of Grays rights, especially the 2nd, 4th, and 5th amendments) is not the concern of the van driver, once Gray is in the van the decision to arrest has already been made
Baltimore Prosecutors Say Freddie Gray Arrest Was Illegal Before Finding Knife - WSJBaltimore Prosecutors Say Freddie Gray Arrest Was Illegal Before Finding Knife
So just let it go with "oops, my bad"?