Are tinned foods safe to eat cold from the can?

Wikipedia tells me that butter beans are toxic and need to be boiled for 10 minutes. However the tinned butter beans at Morrsions have cooking instructions that say "Heat gently for 2-3 minutes. Do not boil as this will impair the flavour." Can I assume from this they are already cooked and can be eaten cold from the tin without warming up? Does this apply to all canned foods?