A recent spectroscopic experiment identified difluorothiophosphoryl nitrene (F2P(S)N) and found that it showed rich photochemistry. However, a discrepancy between the experimental results and the quantum chemical calculations was reported. Thus, high-level ab initio calculations using the coupled cluster singles and doubles with perturbative triples and second-order multiconfigurational perturbation theory were performed to elucidate this inconsistency. The discrepancy arose due to the failure to consider the triplet state of difluoro(thionitroso)phosphine (F2PNS). In this work, we identify that the global minimum of the system is the triplet state of F2PNS, which allows us to explain the inconsistency between the experimental and theoretical results. All calculated results give consistent results with the recent experimental results.