[1.52] Turtle trading locks up villager

How to replicate:

Place a turtle overtop a villager, place a valid trade input in slot 1 and run turtle.placeDown().

The command will return True. No trade will take place. No item will leave or enter the inventory as a result of this operation. The villager will look at the turtle. You will be unable to interact with the villager. Moving the turtle out of range does not free up the villager (the villager continues to stare into space). Breaking the turtle does not unlock the villager. Only exiting the world and re-entering will free up the villager.

I'm not sure if trading with turtles is supposed to be a fully-implemented feature, but the current behavior is bugged.

I also highly doubt that you were ever meant to trade with villagers without a peripheral. (Now that I've seen this, I'm making such a peripheral. I'll credit you.)
However this behaviour is rather weird ans should be fixed, while not at highest priority like world-destroying issues.