Well, if you can assume the watch didn’t see the tanker it’s not that much harder to assume they did not see the tanker + Aldis lamp.
As far as the AIS, if the watch was unaware that tanker was there there’d be no reason to look up the name.
In any case if OOD or JOOD was conning and wanted information they would have asked another member of the watch to provide it rather than leaving the conning position.
That was my experience at least when I went to sea in the military, very serious about watching forward at all time