Well look, there is a risk everywhere. I think that the credit card chargeback rate is about 20-25% and merchants take this risk on themselves. But you are also using a logic that person that paid $3 for a cup of coffee won't be doing a chargeback. It's not worth a risk.
We can use the same logic about the Bitcoin double spend. But if you are looking for a 100% solution, I guess that Bitcoin is not ready for paying a coffee like Ciyam has said above. Honestly I am not sure that this will be ever necessary in order for Bitcoin to succeed.
Mickeyb, you are thinking "western" here. The Philippines is not western. It is an under-developed third-world country. Less than 20% of adults (those 18yo and over) have a bank account. Less than 5% of all shop purchases are made with a credit/debit card.
Yes, a cup of coffee costs about USD2 to USD3 in the Philippines, but that is almost half a day's salary for most workers. A graduate engineer in the Philippines earns about USD15 per day. A shop salesperson earns about USD6.50 per 10 hour day.