He shot at me from lower B with a deagle, so moved further along to a none exposed position, lined up the visible corner of the crate with the flat angle of the wall and aimed at what I approximated as head height where the wall above b tunnels is thinner. It doesn't often work but the occasional spectacular headshot can be quite satisfying.
On this occasion I don't think I even hit him, didn't get any metal-hitting-flesh sound feedback and certainly didn't get the head shot I'd hoped for, I fail to see the issue with that particular shot or spam.
I tend to post my first person demos so you can see it from my perspective too, you don't have to watch it - entirely your own prerogative - I know it's a very long demo.