You are incorrect. The UK has receiprical agreements with many countries regarding the legallity of tempory driving arrangements in the UK, and the UAE is one of them.
The fact that most other countries drive on the opposite to UK, bears no relevance to this.
I can hire a car in the US, UAE, etc etc on a British DL, the same goes for someone with a UAE DL in the UK and US, and ok for someone in the US to drive in the UK and UAE on their US DL.
Extract from DVLA
5. All other countries
You may drive vehicles up to 3.5 tonnes and with up to 8 passenger seats, provided your full licence or driving permit remains valid for up to 12 months from the date of entering the United Kingdom. However, you may only drive large vehicles which have been registered outside GB and which you have driven into the country.