I've not found a tobacco flavour that tastes or smells much like actual fags. Also, I am told by those around me, whatever smell they give off (caramel, vanilla, gingerbread ...) is quite faint and goes very quickly. I think it's unlikely you are smelling fags from the vapourisers (the cig-alike ecigs are just small and not very good vapourisers).
However, lots of people vape as a way of smoking less, rather than giving up altogether, so it's quite possible you have a colleague who still smells of fags. Hopefully they're not actually smoking in the office though.