I think we all know what kind of situation this is.

I don't. Somebody tell me what kind of situation this is?

A shitty one

It's a bad one of course!
(Notice how I avoided it and take it sarcastically)

In the time they spent standing outside your shop, they probably could have found a bathroom. Not your fault, especially since you didn't know and you weren't supposed to be open anyway. I do feel bad for the lady though.

So you were supposed to open just so she could shit herself in your store instead? Maybe she should've gone before leaving her house.

She probably even was. Or at least tried. When you are that old, digestion problems can be a real pain in the ass.

Agreed! My 84-year old father has many health problems. It's in many ways like dealing with a little kid. Make sure they have their hat and mittens, their fly is zipped and they used the toilet before you leave the house.

When you are old and you really gotta go, there is no excuse.

I feel bad for the old lady, grannies often can't hold it and every bathroom break ends up being a desperate race to the porcelain.

But like you said, you had no way to know she needed to go. And even if you did, many stores have really strict policies against having non-employees in the building outside of normal operating hours. Especially if you are part of a big corporate chain of stores, you can actually be fired for opening early.

So I get why the old man was frustrated, but FYL because you didn't deserve to have that taken out on you.

Uhhhhh. When you have trouble holding it you get a thicker skin for going behind some bushes. Her husband was right there to keep watch.
If its someplace without said bushes, then the chance of another store being open somewhere else increases.

Its a bad situation all the way around but you had no way to know and don't carry the fault here.

Something here smells a little off. I wouldn't trust the man OP, but rather the wife. We know she isn't full of shit.

That's a shitty situation

People today are narrow minded idiots.