When the parachutes were opened at 250 MPH on top of the train the body is yanked back with more force than a paratrooper deploying the chute in a head-long dive at 200 MPH; typical speed for deployment is 120 MPH with a G force of up to 6g. The train-top deployment would result in g-forces of up to 12g, possibly leading to loss of consciousness and injuries like neck strain, aorta tears, and broken bones.
The parachutes have only backpack-style shoulder straps with nothing to keep the traps together in the front and no lower straps; when deployed it would be torn off the body.
Power lines above track every 100 yards or so, would prevent proposed tether rescue by helicopter.
But disappear when copter hooks cable to train, only to reappear 2 seconds after copter crashes.
When Kessler is on top of the train, his clothing is being pulled in the wrong direction, taking wind and direction of travel into account.