I'm not sure what the distinction is between "volunteer brigade" and UAF ... are you referring to the TDF? I thought they were under the purview of the UAF.
Regardless of how he got there, I'd seriously question whoever accepted him back into front line service
You appear to have a textbook view on this, which ignores practically. People with missing parts are people, and are useful, and still need to be used.
The tradition for this goes back to and beyond Captain Hook and peg leg Sam.