Before we all jump on the bandwagon take a moment to read this:
Transportation Safety Board of Canada - AVIATION REPORTS - 1998 - A98H0003
How many of the causes and contributing factors the SR111 investigators identified in their final report are/could be the same here in terms of smoke detection etc? The crew cannot be criticised in their turnback decision - they and may learn lessons for the future and apply those in the future for safer flight.