I disagree. You can be nervous to the point where your hands shake and play football just fine, where as if your playing pool and your hands shake then your in trouble.
This is why I answered golf. Golf is more forgiving when it comes to tremors.
You must not have the experience of trying to hole a 5 foot par putt under a lot of pressure. Putting with shaky hands is just as hard as shooting pool with shaky hands.
I would say that both are pretty equal. In either sport, if you let the pressure get to you, it will cost you. What it costs you all depends on the game you are playing.
Golf: Will it cost you a stroke or two on that hole? If match play, will it cost you loss of the hole? If you miss a putt to make the cut, it could cost you 2 extra day's play... plus a paycheck. It all depends on the course you are playing, the format you are playing and when you let the pressure get to you.
Pool: Does it cost you a rack, a match, a cash or a tournament? I guess it depends on when and how you miss, and also who you are playing. It could cost you big, or it could cost you nothing at all.
If I was playing a weak opponent in the pool room, it would be easier for me to handle the pressure playing pool. The simple fact of knowing that I won't pay for every mistake I make takes quite a bit of the pressure off.
If I am playing a strong opponent on the pool table, it would be easier for me to handle the pressure on the golf course. If I make a mistake on the course, I have the opportunity to make up for it, to a certain degree. If the pressure gets to me against a strong opponent on the pool table, I might be sitting there watching them move beads for a while. This increases the pressure.
OP - In response to your original question, the answer is clearly:
"It depends."