This is not a sudden turn of events. there was never one defining moment when things turned the proverbial corner. Just a series of little things. As we all know these little things can make a big difference.
Onion bajis had a distinct taste of Freezer burn.
The korma sauce seemed a little to close to vanilla pudding, or at the very least custard. Really not the best thing to go with shrimp.
Nan bread arrives cold. Is one of the best things about Indian restaurants the straight from the oven bread?
An eggplant dish had a base that seemed suspiciously like jarred tomato sauce.
I could go on but one gets the picture. It has gotten to the point where the very notion of eating there turns one off. It is hard to go to a place knowing that one dish (minimum) will be bad.
I certainly understand that the restaurant business is very difficult. There is a constant need to check and keep cost down. But there is cost control and then there is vanilla pudding.