No, it doesn’t but it’s irrelevant. It’s said a Colt revolver (or the clone in this case) spells it’s own name when cocked, C O L T with each click the hammer makes when cocked. C is the click of the trigger on the safety notch. O is the trigger passing the half-cock notch. L is the cylinder bolt locking into the cylinder. T is the trigger engaging the full-cock notch.
For the cylinder to line up the primer with the firing pin, the cylinder bolt would have to pop up into the notch which happens shortly before being fully cocked. If this doesn’t happen, the cylinder tends to roll backwards as the hand retracts as the hammer is lowered.
But let’s say dumbo cocked it far enough for the bolt to engage the cylinder notch but not far enough to go into full cock and released the hammer without being locked at the full-cock position and never touched the trigger. The nose of the trigger still has to pass over the half-cock notch and the safety notch before striking the primer. Now let’s say that work was done on the trigger or was damaged that the hammer wouldn’t stay at the full cock position or was so light that the hammer could be pushed forward by hand off the trigger nose. You still are going to have forward movement stopped by these same 2 notches on the hammer.
Now of course this is all dependent on the revolver being in proper working order with no damage to the trigger nose. However, this should be fairly obvious with a quick functions check that should take less than a minute rather than the 10-months it took the FBI to conclude that it was in good working order and functioned the way it should. Bottom line is that he pulled the trigger, period!
Now as far as transfer bars go, the reason they came about is on the originals, if the hammer was completely lowered, the firing pin is now resting on the primer of a live round and a sudden shock to the hammer when dropped for instance, can result in the weapon firing. The 2 common solutions here are either to rely on the safety notch (remembering that any safety device can fail) or the more common method of “load 1, skip 1, load 4, fully cock the hammer and lower it down on the empty chamber” which turns your 6-shooter into a 5-shot gun but can in no way discharge a round if dropped. The transfer bar simply allows you to safely load 6 rounds with a live round under the firing pin without fear of a discharge as the transfer bar physically blocks the firing pin from making contact with the primer until the trigger is pulled.