I don't see many individuals at risk of arest, during an emergency situations. An LEO has bigger thigns to think about than arresting you, if he is looking at your stash of food to take it and distribute it. I think the risk you have is from someone taking your stuff, and if anything else harming you. There's not likely to be time that someone wants to spend detaining you or caring for you afterward. They'll just take the stuff, and incapacitate you, if they need or want to do so.

Prosecution for hoarding will not come until there is an up and running system, courts, cops without bigger problems, etc., and then it will most likely be fines.