I Don't need no Excuses!

I picked up a girl on Dame Street going up to Thomas Street, (a short trip), as usual I asked was she coming from work, or had she been out and about, (don't say that out loud if you're Canadian).She said she'd been out with colleagues, but got a message saying a flatmate had forgotten his keys and when would she be home to let him in. That was why she was so early going home.
We arrived at her destination and I looked around for a stranded individual but to no avail. I thought little of it, drove up the road a little and did a U-Turn and as I passed the chipper I saw her in there on her own ordering a take-away.
I assume the stranded flatmate tale was one she used to escape her colleagues, but why continue it in the cab??