I understand that day, from what i've read, you had with you what could be classed as the 3 foremost experts on rock art in their respective areas. ?
Inquisitive jovial sorts who's laugh in the face of conventionality.
I disagree about the "unconventional and jovial" justification, it just means people that don't care what others think. As for the expert bit, have these marks been accepted as man-made by anyone other than this group? Maybe they got it wrong, and they're natural? One of them said - "the majority of Wessex archaeologists are academically illiterate when it comes to identifying such carvings". Sounds like "Wessex archaeos don't agree they are man-made" to me!
Archaeo's never take a positive light on anything, unless they're the discoverer and there's something in it for them.
I could point you in the direction of newly discovered sites/ra that the area's archaeo's refuse even to visit. !