My grandma got locked in two weeks ago the parking lot (gates close around 1am.) How was she supposed to get out? She is very shy and didn't want to ask and she was embarrassed, had to wait until 5am! She said she did not see any signs about this

That's very unfortunate that happened. If there wasn't any signs clearly stating that the gates will close then Vons is at fault and she should be compensated in some way. Two if your Grandma doesn't have the courage to ask for help in an emergency she shouldn't be left alone to complete tasks on her own.

The gate farthest east opens automatically when you drive up to it. Something sounds funky about this. After hours people are stocking shelves and people come and go out that gate. And a stranger just sitting in their car would warrant questioning to make sure their not casing cars. The gates do not open until 6 am so your posting sounds fake.

Don't go to places that would do that ever