I'll likely get slammed by some EE that shows me some fundamental thing that I am missing here, but I have noted some things in my electrical life that may be of interest here.
OHMS law is great and all but it seems to have one "flaw" that I have uncovered in automotive applications. Now first let me say that I do not dispute the laws of physics, or electricity. My observation is simply this. 12v = 1ohm * 12 amps. Use an ohm meter on the bench and I see 1 ohm. Hook up the circuit and I measure 10 amps with an inline amp meter. I go back thinking I have a power supply voltage problem. Nope, total voltage drop is 12v. What happened?
The bulb got hot. Resistance changed when the bulb was 600 degrees f or what ever temp it turned out to be. Any chance the unexpected results some have gotten are related to this behavior?