In reading the report, I empathize with the crew. (Are such conditions frequent at Prestwick/Glasgow, etc?) Pulling the CVR breaker was the right thing to do.
Canadian winters do occasionally provide skating rinks for runways and one never knows which section of the runway will be the most entertaining, even with good runway condition reports and urea or sand treatments.
While the current SOP is to select only idle reverse in order to save fuel and maintenance costs, a handful of reverse early in the landing roll and held, as Davies says, "until the engines object", (keeping in mind that high reverse at low speeds can swiftly reduce visibility to zero on snow- covered surfaces), with medium autobraking for evenness of application and a groundspeed of dead-slow, (< 5kts) as early as possible commensurate with directional control, can be required to keep the aircraft on the paved surface.
Obviously, in poor conditions, crosswind limits are very low.
Even then braking action can actually be nil, especially at the end of the runway where the surface underneath the light coating of innocent snow can be more slippery than the landing surface just used. Ten knots of groundspeed can be too much; also, the aircraft can "sail" with the wind should there be any, while taxiing or maneuvering on the ramp, especially if weather-cocked and presenting the entire fuselage to the wind. Tail-mounted engines in high-reverse settings could act as a drag-chute and pull the a/c downwind, so again, one had to be careful.
There was an excellent two-day "Winter Ops Conference" put on by the Air Canada Pilots Association last year around this time in which these issues, among many, including the
Canadian CRFI, (Canadian Runway Friction Index - pronounced 'surfee'), were discussed.
PJ2