1995 Toyota T-100 driveshaft broke away from transmission

Transmission problem
1995 Toyota T-100 4 cyl Two Wheel Drive Manual

Brought my truck to a nationally known transmission shop with a blown transmission. They changed out my transmission and I brought the rear drive manual transmission home. I started on a long trip and the U-joint (attached to the drive shaft where it enters the transmission) gave out after less than 100 miles, about 70. I was doing about 70 and driving straight down the highway. I was asked and told that I may have, hit something on the rode, I did not see or hear anything. The u-joint gave no indication of being bad before or after I brought it to the shop (I never heard or felt any sloppiness, noise or vibration) the driveshaft broke a piece off the new used transmission, disconnected the emerency brake cables (when I set the emergency brake when I stopped, the drivers air bag deployed?), Ripped the drive shaft loop support off the bottom of the truck, tore up the drive shaft, and I didn't see the rest. My question is, Should the mechanic be held responsible for not inspecting and notifying me of the U-joint condition? The U-joint was old enough that the rubber had started peeling back from the metal (saw this when I got it back to the shop). The U-joint is the U-joint attached to the hub attached to the spline entering the transmission. I paid 2000 dollars for the trust and quality, I could have changed out the transmission for less than a 1000 and changed the u-joint (I'm old and tired). The Lord has taken care of me, I'd rather pay a young family than do it myself. I'd like to be fair so I will listen to all help given.

God Bless
Roy