First of all... prayers for her return.
I wish we could establish if it was just "one male friend" or a male friend and someone else at the house. While 5PM seems a little early for "Netflix and Chill" perhaps not if you have a small window. Whereas if there's another friend there... more than likely everything is strictly plutonic.
In cases like this, I do look out for "code words." How many times have you guys had friends/family over and have actually taken the time to physically see them drive away? I've walked gal pals to their car. But to actually wait to see them drive away... this ain't Beirut. Sometimes perps go overboard with the details... just because they are trying their best to be transparent. By saying, "I saw her..." gives the LEO's what they want timeline-wise, and theoretically clears themselves by stating, "Well... she did leave my house... cause I saw her... so it definitely isn't me!"
Again... I could be way off. But like many who have posted here, just like the missing CO woman, and so many others, that intimate person who has that last confirmed sighting...