That is sad news indeed...I'm sure the paramedics did the best that they could given the nature of their job...they are there to help and it's a sad fact, but mistakes can occur no matter what training they have...
I know none of that will help your uncle right now, but take heart in knowing that their intentions were not malicious in nature...
I hope he's that one in a million and that he will, over time, show signs of improvement...it's a sad situation for you and his entire family...he's in my thoughts...