Thanks for the link, punkalouver.
While the Calgary report mentions several times the failure of the Tower to alert the crew of the fire, it also chides the crew for excessive reliance on cockpit indications of a fire.
I find it strange indeed the failure of the fire warning system is not highlighted. An uncontained failure in the engine cold section should have been immediately indicated in the cockpit; that's a "given" for transport category aircraft. Without such a warning, the crew were working on ambiguous data - no clear emergency at that point.
I've never been in a 737 cockpit, but I doubt one can see the engines - maybe not even the wingtips. Without a working fire warning system, I cannot fault the crew in this case.