That part made sense to me - Kerry picked him - he couldn’t easily diss him. But if someone really wanted to read between the lines, the coolness was probably there.
The other interesting thing was that in 2004 Kerry made Edwards promise to a “non-compete” - that Edwards couldn’t go up against Kerry, unless Kerry decided not to run. I think I remember that playing out at the time - Edwards waiting for Kerry not to run - out of “loyalty” it was said at the time - when in fact it was a quid pro quo.
Now that you mention it, I remember that agreement also.