I just heard about this. I don't know to much about Allen but I do know he was the head coach at Penn State. Here is an article i found on the report.
http://www.ttownsports.com/?p=1119
Penn not Penn State, he coached in the IVY League, played in the IVY League for Penn, and played in the NBA.
http://www.masslive.com/celtics/index.ssf/2015/07/brad_stevens_incredibly_impres.html
Has a pre-existing relationship with Brad, was not successful at Penn as a head coach but Brad seems to really like him.
I graduated Penn a year before JA and got to watch him for four years. Obviously, the competition in the Ivy League isn't exactly the ACC, but he was clearly head and shoulders above the rest of the league. He is
exactly the type of guy that CBS will love. He's a good "fundamentals" guy and he worked his butt off. He and Matt Maloney, who also went to the NBA, were probably a Top-10 backcourt. Our problem was that we had a 6'7" center.
Mike