Thanks for the replies.  Sorry, I should have shared the whole story.
The other guy, thankfully, came off better and I suspect had lesson momentum.  He grazed one of his hands quite badly, but was taken home by family.  Appears the bikes clashed frame to frame, and we both continued onwards.  I am glad, of course, the frame absorbed a significant amount of my momentum.
The kind GP who stopped at the scene,  and called the ambulance, said I was stunned (hit my face, was wearing a helmet but not tight enough and even then jaw is not protected), and so I had to go to A&E and get asked the questions.  I was OK, so soon came home.  Just got a maybe a little concussion, but not enough to forget anything, and a few scratches, bruises, neck ache and had a mild headache yesterday.  I was allowed to work from home today. 
Yeah, if anyone would pay for postage they can have the frame, possibly life in the fork. 
I think I may stop using this stretch of cycle path and simply cycle on the road from now on. 
Oh, to cycle commute in Holland 

Grass is always greener!