“She was holding a locking primary acess door open for her dog when a person she didn’t know forced his way past her and refused to show his key or fob to open that door.”
There is no evidence that he forced his way into the building.
Instead, he entered the building where he has an apartment.
If she had voluntarily let him in and he was not a resident and attacked someone or burglarized a unit she could have been held civilly and possibly criminally liable.
Why didn't he have his security fob?
If he didn't have it then he calls the apartment manager to be let in.
Why you refuse to see this as a basic security precaution is beyond me.