Hi,
Terrible idea for several reasons.
If someone finds it before it dies the we are right back to the bad for the hobby argument.
If it can't survive to become and invasive species because of the environment then you are intentionally putting it into an environment knowing it will kill it - hardly a charitable act.
If, as you are discussing, the animal is ill/ deformed then you are not magically excused from your duty of care. Putting it out into the wild is not caring for it. Either help it live happily or help it die humanely.
It is also, in all likelyhood, completely illegal to release it into the wild.
dr del