My biggest concern would be causing an amonia spike due to the feeding frenzy. If its a small fish, it may not be an issue, but a larger one would be. I'd get it out of the tank as soon as I noticed it. I suppose you could portion it up and feed it back that way, thus controlling the waste volume and avoiding the spike. Just not sure how well I could handle mincing and chopping my once prized specimin.
I think for the cost of food, I'll just continue to salute and flush the dearly departed.