Unfortunately, Dr Grant was wrong, and this theory only comes from Jurassic Park and is not accepted at all in paleontology.
I will use this article , but there are a lot similar on the web that answers the same question.
The T-Rex has a very developed sense of smell, so the "don't move" theory is already broken by that fact.
Furthermore, he has front-facing eyes, and his binocular range was 55 degrees which is actually greater than that of a hawk.
You can find other crispy details in this article if you want some more infos!
