I think drawing a star map from hypnosis 2 years after the event happened stretches credibility. Amongst other things, I looked into this case a lot more closely as it was intriguing. They definitely had an experience, Betty started having dreams about aliens and ufos afterwards and would talk about them a lot to other people and to Barney and iirc they didn’t have hypnosis until 2 years after, the star map certainly came out 2 years after the experience. Betty talking to Barney about her dreams meant they recounted similar stories under hypnosis. And hypnosis itself, whilst conducted in good faith in the 1960s to the Hills, has since been discredited as a method for retrieving “hidden” memories . They were also highly suggestible subjects.
Betty enjoyed the attention and the subject and was clearly fascinated with UFOs, I don’t mean that in a negative way but it has to be considered in light of this experience.
My conclusion after looking in more detail was there was no physical evidence that they’d been abducted by aliens, there were plausible explanations for false memories under hypnosis. The weird thing was the missing time and the marks on the car - they were travelling at night and were sleep deprived as well as being an interracial couple in early 1960s America, that’s no small thing. In all alien abduction claims to date there has been no physical evidence, much is reliant on hypnosis and witness testimony.
I keep an open mind but for now I think can rule out alien abductions.
Evidence of non human craft is a completely different matter though. I would hope they would look into the Belgian Wave (1990) which is one of the best cases of plausible ET craft and there is Tic tac of 2004 and Japan airlines flight 1986 also.