Tree branch / water pump/ new motor?
 

Need some help. My son was driving down the hiway and hit a tree branch, as soon as he hit it the low fluid light came on to shut down and pull over, he looked out his mirror and fluid was all over the hiway. The car died as he pulled over.
Had insurance take it to a dealer and they are claiming they see no tree damage on motor area and fluid was coming out of the side of the water pump. They are saying tree didn't cause damage, it's a bad water pump causing the timing belt to jump and it destroyed the motor so they want to put in a motor for 5k.
My quesiton is. I just was under that car and in my drive way with no water leak at all. Could the branch get on the serp belt and cause the timing belt to jump. Does a bad water pump really take out a motor?
Thanks.
Any advice