I've learned a little more. First off, before I "picked up the frame" I had been manipulating the hammer. This in fact releases the tension on the trigger bar spring, which, when tilting it just right, allows for trigger removal. If you leave the hammer alone, the tension from the trigger bar spring holds the trigger in place nice and tight. The lesson: when you field strip the gun (unless you want the trigger out) do not manipulate the hammer.
