Depends on the procedure, Jim.
If, for example, the investigator finds spalling and equates that with an incendiary fire, then points to a stadium full of like minded folks, he's still wrong, and so are they. And he's still likely to be found to be negligent for not keeping up.
For years, there were folks who believed, taught, and made arrests or denied insurance claims based on a bunch of myths. They were outside the standard of care in 1992,and 1995, and maybe 1998, but still represented the majority of the profession. Thanks to NFPA 921, there are not as many believers in myths as there once were.
John Lentini, CFI, D-ABC
Fire Investigation Consultant
Florida Keys
[
www.firescientist.com]