programmable “man-down” button
This alone mandates the use of a professional radio. I dont know of any thing but that supports this. If you are needing something with this, I strongly urge you to seek the assistance of your organization to provide accordingly.
Need a little more on freqs, is this 150s, 400s and/or 800s? You can find a lot of ham radios that can work on 150s and 400s; as this is a normal dual band ham band set. Might take some slight modifications to get it to work in 150. 800 is normally a professional radio only (Motorola, Harris, etc. ). That said, if its not 800, any ham mobile that you can find to work on 150/400 will work. I dont think any have "man-down" functions for mobile, only handhelds.
As long as he is authorized, there should not be a problem. If his locality is ok with it... why wouldn't you be?
Legally, he still needs this in writing to be able to use (transmit). Many departments say its ok, but dont have it in writing (Im having this fight with my own department right now). Oftentimes its because they dont understand their own licensing and the legalities surrounding it (which is partly my problem).
My guess is Motorola/Harris/whomever had them sign a form for obtaining their license, but didnt explain all the details surrounding the use of it.