I was the safety officer at a glider operation earlier this year and we had a new tow pilot who forgot to drop the rope. By radio, I instructed him to drop the rope before landing. The downsides of this is that it would temporarily leave the rope in the middle of the grass field where an aircraft might run over it, and also someone would have to golf cart out to retrieve the rope.
Later, when he found out about it, the chief tow pilot got angry about this and said the tow plane should have landed with the rope attached and dragged it back to the launch location. I thought this was unwise because this could damage the rope, or if the rope were to catch on something as the plane landed, it could have dangerous consequences for the tow pilot. Also, I have seen loose tow ropes whip around. Considering that there is a metal buckle at the end of the rope, imagine that thing whipping around. If the plane landed with the rope attached, I was picturing that buckle whipping into a bystander or a parked plane.
Of course, the third possibility is that he could do a go around, fly all the back and do the rope drop correctly. The disadvantage of this is that it would delay the return of the tow plane for another 10 minutes while he did the go around, and we had multiple people waiting for tows.
What is the best procedure?