Poor Freek

Really dodgy people try to extend the life span of their product, by cooking food of dubious quality.... Did you eat the oyster in canberra?
Usually you can tell from the smell, as to how old the oyster is.
If it smells "of the sea", all fresh, and looks glossy/shiny/healthy it's nice and fresh.
If it smells still good, but doesn't evoke those scent's/feelings, and is still brightish they are perfectly OK to eat, but not the freshest ever.
If it smells strong or "fishy", looks dull and dry, nd just not very nice, chances are it's not. I wouldn't eat it.
Of course, if it is sitting in a shot glass of vodka, well then you might have a little more difficulty identifying colour/scent, especially after a few!

Matt: I've heard of doing oyster shots in bloody Mary's, but plain vodka could still be good!
QUOTE
Are off ones runnier than normal ones? Or is it just random luck when you eat them?
Err... maybe if they's REALLY started breaking down, but I think you'd be able to tell by then....