Blocking a dangerous overtake

The driver in this instance tried to overtake in a section of the road where there's a concrete island that narrows the road quite considerably. There was nowhere near enough room for me and the car in that spot, so I waggled around drunkenly and threw my arm out to make them think - and give up on overtaking. As it turned out, they immediately turned left, so if they had overtaken, they probably would have taken me out as they turned the corner. Another bullet dodged.