Doesn't matter. Dont be sorry. Many including me have made this mistake in the past, to get off at the international arrivals and think we can relax over coffee for some time. In most places, I know it is not possible. I had two experiences of traveling to Goa after arriving past midnight at CSIA in the last couple of years. First time, I had a 5am flight to Goa. I had to transfer to the domestic airport immediately (as there was no place to sit) and domestic departures had seats but no food outlets were open till 4am and because of security we were not allowed to leave the terminal for a coffee. The next time I was wiser, I booked a small hotel near CST, too a cab slept for 3-4 hours and caught the Mandovi. For business (very few people actually wait at arrivals) and security reasons (they...
more... dont want people to stay for too long) they have a almost direct exit after the customs.
THat is why, I am extra careful in giving advice to people who arrive at international terminals