It is wonderful that your friend was able to find his dog. The people responsible for the dog's survival and return are heroes. I think without one of them doing what they did, the dog might have been in a worse state. I hope they are more careful with the dog in the future. If it can get startled and run off, it might be good to cover all exits.
He is going to get a GPS collar for the dog, as if it really wants to run, it will run. It weighs 45kg and can pull very hard.
Ah, that makes sense. With how big it is, blocking the exits might be a bad idea, and it could destroy things, or injure itself.