This puzzles me because people with your kind of experience don't make the assumptions and mistakes you are making in your post.
No need to be puzzled -- I make mistakes all the time.
I really was not trying to pass judgment on the PIC -- I was asking an honest question. The factors you've mentioned didn't weigh as heavily in the thought process I used.
Number one rule... when you evacuate an airplane using slides... people WILL get hurt.
I considered that there would be a risk of passenger injury, but did NOT consider it to be an absolute given. I also considered that an orderly evacuation using the L2 and R2 slides might have been more expeditious than waiting for stairs, and wouldn't necessarily involve the obvious panic of a more dire situation, i.e., actual fire.
I don't believe there was a fire. You cannot deny, however, the potential for a fire. My concern was the POTENTIAL for a fire. What if (I hate "what-if-ing", yet here I go) a fire had erupted near the nose while I was waiting for the stairs. THEN, I would have had no choice but to direct an emergency evacuation without the L1 and R1 slides (due to the proximity of the supposed fire) complete WITH the panic and PROBABLE injury to pax. Then I might be kicking myself for wasting those precious seconds doing nothing while waiting for the stairs to arrive. Besides, who knows -- maybe the PIC WASN'T "doing nothing." Perhaps he was lining the pax up in the aisle so they'd be ready to use the aft slides if they needed to. Maybe he was movong them all to the back to shift the CG and lift the nose off the ground so they could use the aft stairs.

[Editor's Note: That was supposed to be funny.]
Many people have been seriously injured or killed due to evacuating an aircraft because of a "lightbulb"... ie a faulty indication. Granted this wasn't the case here, but importatnt to point out nontheless.
You're exactly right. It was obviously more serious than a lightbulb. And I guess it boils down to a judgment of how serious the threat of fire was. Personally, I wouldn't hesitate to use a slide. But then again, I don't carry PAX, so I suppose I see things in a different light.
Once again -- I wasn't intending to second-guess the PIC. I sought, and continue to seek, a higher degree of understanding. I appreciate your patience, and I appreciate your enlightenment.