I'm thinking you got something else going on there, I've eaten gumbo that sat out on the back of the stove for a week just re-heating it for a meal and putting the lid back on it then shove it to the back of the stove. Never got sick that I noticed... We done the same with red beans and fatback and even beef stew.
2015 Keystone Cougar 333MKS
2015 Ford F-350XL 6.7 CC, DRW, RWD
(Finally enough tow vehicle 14,000 GVWR 6062 payload)