If only there was as much as 3 or 4 inches of snow - it usually only takes 1/2 an inch to cause chaos. Having checked the BBC video it looks as if it's about an inch at worst on the taxiway.
Yet again this is superb confirmation of the absolute lunacy of putting all your transport eggs in the one basket [case] of Heathrow.
Inadequate equipment provided to keep if operating under conditions which would barely be remarkable in other parts of the world and which have happened there before, and when some snow falls everyone is SO that it can't cope! I can only hope that the diverted passengers hit BA/BAA for enough compensation & the non BAA divert airports hit them for punitive landing fees, that it might bring them to their respective commercial senses and get them to think about the wisdom of at least two or even better three geographically distributed medium sized hubs over a single creaking, overloaded, cramped and hamstrung hub. Maybe of this happens some good might come out of this shameful event.