I'm not sure the Toronto and Heathrow cases are exactly comparable.
As I recall, the A340 incident happened after at least one go around in poor weather probably causing a fair amount of anxiety within the cabin then managed to cause a fair few injuries amongst the SLF as well as destroying their belongings.
In Heathrow, it is apparent from most of the statements that few of the passengers were aware of anything amiss until the plane actually dropped short of the runway. Secondly, those unfortunate few who were injured suffered relatively minor injuries and finally the damage to the cargo area of the 777 at Heathrow appears from all of the media coverage to date to be relatively minor, therefore although the passengers are likely to have suffered the inconvenience of not getting their luggage straight away, they should still be able to reclaim it at some point, probably substantially undamaged.
Frankly, it's disappointing to see that litigation is being considered, as it brings us that much closer to the litigous culture that exists almost unchecked in North America. I would have hoped that the passengers would have been sufficiently realistic to realise how lucky they were to walk away and appreciate any efforts the Company would have been able to make towards recompense and restitution.
I'm not sure just how U.K. law stands on this versus how it would be viewed in the U.S. I suspect that the defendants might have a harder time had this happened on the other side of the pond, say IAH, EWR, ORD, or MCO.........