Am I being overly fastidious?

We were at a very high-end restaurant in Chicago last night and had the privilege of watching the kitchen work. At one point, to my utter astonishment, I saw the sous chef take the spoon in a saucepan, put it in his mouth to taste for seasoning, and then replace the spoon in the saucepan. Later he used his finger. I will refrain from rehashing the arguments pro and con.

My only question is, am I being overly fastidious in finding this unacceptable?

You're right, this is completely unacceptable.

They should know better than to practice normal kitchen behavior when they're being watched.

Mike,
who never picked up a fast food burger bun from the floor when a manager was looking right at him

Not at all. That's disgusting. When I cook, I always have "tasting" spoons handy.

The worst thing I ever saw (and I was a restaurant cook for awhile - and you see things you would rather forget) in this regard was watching the frugal gourmet blow his nose into a kitchen towel and the proceed to wipe down his cutting board. I'm still not over it.

Did you happen to go to an Asian restaurant? It might be a cultural thing.

In Iron Chef Japan, chopsticks and other cooking implements are constantly dipped and double dipped and no one ever seems to mind.

I would have to agree that such behavior is unacceptable in an open kitchen, but I'm sure it's a common practice in a lot of establishments.

As someone who's worked in kitchens...this happens all the time. Technically, it's not considered sanitary.
Shame on that cook for doing it when watched as I imagine they could be cited by the health dept.
Theoretically, as long as whatever he or she was cooking was at a high enough temp to kill any bacteria, it doesn't really matter (except that it looks bad and is breaking health code), but if it was a simmering sauce on very low temp, for example, it could be a problem for someone, say, with a compromised immune system (I imagine most people don't get sick from such a common practice because healthy people can rid themselves of small amounts of most bacteria and viruses with no problems).
Remember the first Top Chef episode from last season with the obnoxious Irish guy getting booted mainly for tasting with his finger?