The same thing (incidently in the same place) happened to me last year. I think the point is that we must accept that if we have seen them and they havn't seen us - it makes diddly squat difference whose right of way it is.
In my incident I was on my way back to Redhill, the visibility was the best I have ever seen (looking south-east I could clearly see the Himalas
) yet this guy just trundled on with his head inside not outside. Eventually I just assumed he hadn't seen me, broke off my course and did an orbit to let him clear.
There again, he MAY have been looking out and just missed seeing me. 10 minutes later I may have been blissfully unaware of someone breaking and orbiting to miss me.