Why would anyone want to get up in the middle of the night and drive at their own expense to dispatch an injured deer is beyond me. No one likes to see an animal suffer unnecessarily, but surely a fee should be paid. It totally devalues the profession of a deer manager to work unpaid, or any profession for that matter. If it were a charity such as RSPCA their officers are paid are they not?
It may seem like the kind thing to do, but to do it on a professional call out basis where you are responsible for Traffic Management and any accident which may take place under that management is very un-proffesional. Technically if you don't have a "chapter 8" qualification and the proper signage for any kind of interference on the highway then you can be sued for any accident that takes place. I'll bet the small print states that you are responsible for Traffic Management.
I do call out work for 3 local authorities and the FCS for storm damage tree work, we have to take TM very seriously, bringing in outside contractors where necessary.. I'd be mad to do it for free.
There are people out there just looking for someone to sue, and a whole load of lawyers encouraging them to try....
Don't sell yourself cheap. You de-value the skills of everyone.....