If X occurs in abnormal circumstances (not rolling a natural 20) and those abnormal circumstances do not dictate otherwise, then yes.
Absolutely true. Specific unusual circumstances can change the basic rules. everyone agrees with that.
Per the Rules Compendium:
"Natural 20: If you roll a 20 on the die when making an attack roll, you score a critical hit if your total attack roll is high enough to hit your target’s defense. If your attack roll is too low to score a critical hit, you still hit automatically."
Artoomis makes a good point here though. The rules have the requirement of a successful attack roll before you score a critical hit. Requiring that "scoring a critical hit" again checks to see if you hit is redundant - not logically contradictory, I'll give you that, but it's certainly not needed in the standard case.
Also, allowing "score a critical hit" to include some misses creates some serious unintended consequences.
Suppose I "score a critical hit" but miss on a big monster. With that interpretation, there are TONS of powers that could kick off on that miss, like Font of Radiance, Triumphant Attack and a slew of item powers that trigger off of "scoring a critical hit".
Then, you have the trouble of the other examples and text on critical hits throughout the book.
High Crit said:
A high crit weapon deals more damage when you score a critical hit with it. A critical hit deals maximum weapon damage and an extra...
Critical Hit said:
A critical hit deals maximum damage and some powers and magic items have an extra effect on a critical hit.
Example: Valenae PHB 276 said:
If she scores a critical hit, she deals maximum damage of 23 points and adds 2D6 thunder damage from her thundering longsword.
The very beginning section on critical hits also makes the point that the term "crit" is synonymous with scoring a critical hit.
For those reasons (and others already listed in this thread) I believe that the term crit, critical hit and score a critical hit are virtually interchangeable and simply describe the maximum damage hit we all know and love.
However, all is not lost! Precision still has a place, but you may not be surprised to hear that my interpretation is slightly different than yours. I hope that you will find it consistent with the rest of my argument.
Unfortunately, I'm off to GM Shadowrun right now so I'll be back in about 5 hours. I apologise for making you wait on my take on precision (that's a long post too). Duty calls.