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We systematically investigate the claim by Vandorou et al. (2023) to havedetected the host star of the low mass-ratio ($q<10^{-4}$) microlensing planetOGLE-2016-BLG-1195Lb, via Keck adaptive optics (AO) measurements $\Deltat=4.12\,$yr after the peak of the event ($t_0$). If correct, this measurementwould contradict the microlens parallax measurement derived from Spitzerobservations in solar orbit taken near $t_0$. We show that this hostidentification would be in $4\,\sigma$ conflict with the original ground-basedlens-source relative proper-motion measurements. By contrast, Gould (2022)estimated a probability $p=10\%$ that the ``other star'' resolved bysingle-epoch late-time AO would be a companion to the host or the microlensedsource, which is much more probable than a 4$\,\sigma$ statistical fluctuation.In addition, independent of this proper-motion discrepancy, the kinematics ofthis host-identification are substantially less probable than those of theSpitzer solution. Hence, this identification should not be accepted, pendingadditional observations that would either confirm or contradict it, which couldbe taken in 2023. Motivated by this tension, we present two additionalinvestigations. We explore the possibility that Vandorou et al. (2023)identified the wrong ``star'' (or stellar asterism) on which to conduct theiranalysis. We find that astrometry of KMT and Keck images favors a star (orasterism) lying about 175 mas northwest of the one that they chose. We alsopresent event parameters from a combined fit to all survey data, which yields,in particular, a more precise mass ratio, $q=(4.6\pm 0.4)\times 10^{-5}$.Finally, we discuss the broader implications of minimizing such false positivesfor the first measurement of the planet mass function, which will becomepossible when AO on next-generation telescopes are applied to microlensingplanets.

OGLE-2016-BLG-1195 AO: Lens, Companion to Lens or Source, or None of the Above?