Spotted...

DAS'd lettiemarsh I'm pretty sure outside SOAS early this evening, I don't think she noticed.

Then had to explain to friends 1) what I was doing and 2) why it's totally not weird for me to shout at someone who's bike I've seen online but I've never met or even interacted with on the internet

I was just about to ask who DAS'd me outside SOAS this evening.. so it was you! I was crawling through the crowds so I didn't think it was possible to DAS (what do I know). Internet interaction complete, your friends can stop teasing you now.