Who was at fault here?

[Canada Darrell™]

Personally, were I the "old man", I woulda beat the biker and taken his camera. 
Regardless of the fact the man wasn't using a crosswalk, the biker is 100% at fault IMO...

[Scott]

Absolutely.  Why should the guy have even thought to look for a car/bike coming up the wrong way??  Crosswalks are for people who have plenty of time 

Note the biker was trying to deflect at the end... 

[David]

Bloody cyclists!!

If they aren't riding four abreast on an A road (Jez that pisses me right off that) they are trying to kill the old.

I remember years ago in Belfast seeing an altercation between a cyclist and a motorist at traffic lights. Not one hundred percent sure how it all started but the cyclist banged on the bonnet (hood) of a nice shiny Ford Escort, I think it may have been a XR3 or an RS Turbo. Next thing the driver got out of the car and pushed the guy off the bike and proceeded to try and beat the guy with his own bike. Quite funny. 

[Dare]

If it happened here the bycycle rider would
get his pants sues off.Personally a good ass
whooping would surfice