"It's not so hard" --Sparklehorse

Why is everything way harder than it has to be? I go into the Subway and before I get in line I decide to make use of the facilities. As I approach the restroom, a lady is coming out. I see the door close behind her. I reach for the handle and tug. It's locked.

Bathroom lady (BL): Did it lock?
Me: Yes.
BL: It locked?
Me, trying handle again: Yes.
BL: Maybe they have a key.
Me: Probably.

BL and I approach the counter and speak directly to an employee.

BL: I just left the bathroom and it locked behind me.
Subway Guy (SG): It locked?
Extra-Helpful Woman in Line (EHWiL): I think she said it locked behind her.
SG: Did you lock the key inside?
BL: I didn't see a key.
EHWiL: I think she said it locked behind her.
BL, pointing to me: She can't get in.
SG to BL: You didn't see a key?
EHWiL: She said it locked behind her.
Me: I just need access to the restroom. Can you let me in?
SG: Yeah.
EHWiL pointing to BL: That woman said it locked behind her.

Rest easy, he found the key and I used the facilities.

I say all this to say, what kind of person is the EHWiL? I didn't even need BL to speak on my behalf but I sure as heck didn't need EHWiL volunteering her expert witness perspective. Who does this? BL was speaking directly to SG and she wasn't mumbling or hard to understand. Why are some people self-appointed interpreters? And is it okay to smack them? Because I really wanted to smack her.