I will just say for those that are not trappers WSTA has been trying to get DFW to write some rule changes for literally years to address just these kind of circumstances.
Anybody not just trappers can be put in this sort of untenable situation. It is illegal for anyone to move or release and animal off premises. If you happen to be in a no shooting zone how do you dispose of nuisance wildlife given that your only legal options are to release it on location or kill it.
A lot of the furor over this is that the coyote was drowned. That is not unlawful but not a good option. He should have taken it to the country and shot it but if caught he would lose his permit forever and his livelihood. Also illegal for him to take it to a wildlife rehabilitator. If they wanted that done the police should have called DFW but they don't want to deal with it either so it gets dropped in this guys lap.
The whole thing is a basket of bad options. Perhaps it will spur DFW to reopen talks on some rule changes.