Yes, you and Mr. Carmen are correct. In inverse or reverse flames, the center is an oxidizer-rich gas surrounded by a fuel-rich gas which diffuses inward. In addition to occurring in backdraft situations, they can arise in fires involving compressed or cryogenic gases such as oxygen, chlorine, fluorine or nitrogen oxides. They can also occur in fires involving oxidizer-liberating solid materials such as salts of oxyhalo acids (e.g., chlorates, hypochlorites) and solid peroxides or liquids such as bromine, industrial hydrogen peroxide or nitric acid.