Yes, Majeed, It does seem severe as its easy to buy alcohol in airport lounges even in Muslim countries. Airports are like an international space with a different culture to the host country as they are full of international travellers.

I don't think someone can get drunk on a plane because the flight crew will serve two drinks maximum, but if this person had been drinking for a while before he got on, he might have managed to get one or two more drinks in.