Damage. Who pays?

Scenario:

You're making a run in an owner operator's rig for him, (your an OO too but your a bit slow, and he isn't and he wants some time off. So you jump in his truck for a weekend and make a run for him. Works for both people).

Your on the interstate, in the right lane. Cruise control set at 72. In the center lane is a pick up with a trailer loaded with a huge overflowing load of what looks like assorted scrap metal. As far as you can tell the load looks like it is probably to much for the trailer and the stuff was just thrown on and secured with a couple 2" straps. He is going probably 60-65 so your behind him a few minutes as your catching up to him. As far as you can tell it does not look like anything is immediately about to fall off the pile and into the road.

When you are about 2-3 car lengths behind the trailer you see 1 of the straps let go and most of the load instantly starts to shift and fall off the trailer. You immediately hit the brakes hard and take evasive action by moving to the right as far as you can go and still keep all tires off the grass and on the asphalt. (Remember, your going 72. You really don't want to hit the grass at 70+)

Crap is scattering all over the road and you hit something. Not sure what it is but it definitely hits the driver side steer tire. You pull over and inspect the tire and you find serious damage. It is still holding air but will obviously need to be replaced.

The truck owner wants to take the cost of the tire out of what you were to be paid for making he run. You disagree and he says ok, then he will split it 50/50 with you.

Question is who should pay for the tire?

 

1) Scrap truck driver did not stop. (So no insurance there).
2) I was NOT on phone, eating or anything of the sort. I watched AS THE STRAP BROKE I SAW IT... WHILE IT WAS HAPPENING.
3) I was NOT to close. I was in another lane passing the guy. I was in the right lane. Scrap truck (going below the speed limit and holding up traffic) in the center lane. I am in a "No trucks in left lane" zone so I'm not allowed to be in the left lane.

My choice is to slow to 60 and follow behind the guy for as long as he is on the road or pass him. Until the strap broke there was no reason to follow him at sub-speed limit rate for the next 100 miles so I closely observed the "potential" hazard and passed.

I could also note that his crap scattered overall 3 lanes and dozens of vehicles behind him were swerving, locking up brakes and so forth. Several other vehicles had pulled over to assess damage while I checked my vehicle.

Edited to add: I am not saying I'm some super driver or anything of the sort but.. A less experanced driver may well have shot over into the grass, lost control and wound up taking the entire rig into the woods. I moved over to the very edge of the pavement and was braking HARD before the very first price of metal had even hit the road. Had there been more pavement I would have kept moving over but I'm not about to hit the grass in a loaded car hauler at 70. Not for something like that anyway. Shooting off into the grass at 70 (Or even 60) in a loaded car hauler is almost guaranteed loss of control.

Part of my point is it might have been nice for the owner to recognize that it COULD HAVE been a lot worse if not for a reasonably skilled driver who was actually paying attention at the time and who knew not to shoot off into the grass. Maybe even a, "Good job on not totaling the rig" might have been in order?