An Aloe Vera Plant Killed by Frost

The nice dark shiny green color actually shows the frostbite, the leaves are very floppy. I don't know if it is also root dead. I deliberately left this one out to test how much cold they could stand, well it appeared to survive down to freezing point, but we've had it much colder this year in the UK. All the same I don't know which night killed it, I'll have to be more scientific next year