Re: by a truck towing a truck
It probably was a bit confused that the truck was moving backwards, rather than "thinking" that it was a truck towing a truck. This is arguably what makes AI so impossible.
What is needed in self-drive environments is a "beacon" on bollards saying "no you can't use this lane" and a "beacon" on the towed truck saying "this is not what you think it is, use yer brain". This beacon would be supplied to recovery companies to fix on their vehicles when towing.
*A beacon being something that emits a warning radio signal which is recognised by all self-driving cars.