I had a similar one with a man in 'thobe' and children in a big car... bearing down on me, as I overtook another van. (Thobe wearers aren't always Qatari by the way!)

We (the van and I) were parallel at overtaking point, and this guy came down speeding and flashing lights, swerving between me an the van, trying to get past us. I kept at my correct speed limit 120, and took the correct time to overtake. The guy was in my bumper by now almost.

I had not cut into him, and in fact he was a long way back as I began to overtake, (about 1/2 klm) when I first saw his lights flashing me, buthe must have been doing 200 kms. I reported the incident by phone, and on the MOI website. Never heard anything else, but it covers your back in case of 'revenge' acts, which do happen here.
Angelwings

If the grass is greener on the other side, its sure the water bill is higher !