Just exactly what time is reasonable. No I don't mean for a number of minutes is necessary; I'mt suggesting that, the criteria should be an apparent acknowledgment of what is reasonable, and that is enough. If the trapper, the nutless bastard, hasn't got a clue as to what is reasonable then, do you really want him watching your six.
Go to your local sheriff and find his position on this issue (for certain take a sound recorder). If he's agreed with you, then so will his deputies. If not, push to find a replacement.