During the transition from patch 2.4.3 to 3.0.3 the following talents were not unlearned properly by some players, resulting in those players still gaining the benefits despite the talents no longer existing in the talent trees. As a result, we've pushed a hotfix which has corrected this matter and affected players will longer receive credit for having these talents.
Warlock: Improved Lash of Pain
Warlock: Fel Stamina
Shaman: Totemic Mastery
Shaman: Improved Lightning Shield (Rank 3)
Rogue: Fist Weapon Specialization
Priest: Shadow Focus (Ranks 4 and 5)
We all need to take a step back here and remember how the math behind what we are talking about works. If you had enough hit to put you 1% below the hit cap, whatever that number may be, you could still have more then a 1% of your total attacks miss. If you had a 99% chance to hit, it is still in the realm of possibilities to do 100 attacks (or even a million attacks) and never land a single hit. A 99% chance to hit is also a 1% chance to miss. The chance of getting one miss is 1%^1. The chance of getting two misses in a row is 1%^2 (0.01%). The chance of getting 20 misses in a row is 1.0E-38% chance. Of course this is extremely unlikely, but hopefully you are getting my point.
Multiple tests across all classes while using a 2 hander (no TG) is the best way I see to hone in on what the hit cap is. The larger the data pool the closer we are to the true value.