it tasted a little...funny

Last night's dinner was crab quiche that I had made on Sunday,  and salad.

I'd bought the lettuce and tomatoes and other stuff on the way home from work, so I knew they were all fresh.

Well as fresh as they could be after sitting in a supermarket for who-knows-how-long.

The crab quiche was yummy, but the salad,  seemed a little.......not quite off......but funny tasting.

So I checked the expiry date on my bottle of salad dressing.

Oops!
Time to buy a new bottle.

Now, I've been using this same bottle of dressing for as long as it's been in my fridge.
I've not been ill from it and the food has been alright.
Until yesterday. 
Just another example of how foods do not necessarily have to be tossed the minute they "expire".
Although I did keep this a little too long.