Mystery object in southern sky on Friday Night

I thought that as well. Low altitude, bright stars would certainly
twinkle colors. However, if you note his more recent message, he
compared the sky to his star charts and determined that what he was
seeing was not one of the bright stars in the region.

I'm not going to rule out the star theory entirely. But he is a pretty
experienced optics person, with about 40 years of experience, so I
don't think he's totally off the wall.

But, as you say, if nobody else saw anything unusual, then chances are
that he's reporting some artifact.