I had heard similar, although not in this detail.
Ed Rasimus was the DO when I went through the 435th. He was pretty intimidating to this 2Lt, just from his personal demeanor.
It wasn't until many years later, reading a book about Vietnam, that I discovered I had been standing in the presence of a legend; a giant, in the league of true warriors like Robin Olds.
To echo galaxy flyer: the T-38 is not necessarily an "unforgiving" airplane. The fact that you can take someone with 25 hours in a DA-20, 65 hours in a T-6A, and 11 hours in the 38....and then go solo in a supersonic (capable, although just barely) jet....says it isn't inherently dangerous.
Its biggest limitation is a 5000-ft turn radius at any speed between 220-500 kts.