CAMRA are saying that they had agreed to take 50l kegged beer, as long as it was keg conditioned, but Brewdog wanted to give them 30l key kegs, which CAMRA say would cause them logistical problems.
Brewdog claim that CAMRA agreed to take kegs then changed their minds and demanded casks.
One thing that both sides are agreeing on is that CAMRA did (initially at least) agree to take kegs off them, so this has nothing to do with dispense.
Looking at both stories, it seems rather unlikely that CAMRA would agree to take kegs, then suddenly realise that they don't like kegged beer and try to get out of it.
On the other hand Brewdog behaing like dicks to CAMRA and then trying to spin this into a Brewdog verses CAMRA stick in the muds thing for the sake of publicity, does seem quite plausable.