Telor, have you done anything in the console during the older quest where you had to give Aldam a drink in the mine? Or had any other irregularities during that quest?

That quest is in the Carnius Magius questline, I picked the Falco Galenus questline.
But I have done so much in the console, though.

Do have any gamesave that's actually before you begin using the console command by any chance?

Absolutely not.
I had to use it to work around several quest breaks earlier in the game.
Might I add that was before I got any mods.

And then I had to use it to fix the damage done by a few crappy, crappy mods.

By then I was just using it pretty much willy-nilly. My last playthrough was by the book, I'm entitled a more manipulative one.

Here's what I do for companions who are behaving in much the same way:

1. Open the console
2. Click your runaway
3. Type "GetCurrentAIPackage", hit "Enter"

If it told you -1, you can try this solution -- but SAVE FIRST, I don't know what it will do to a generic follower rather than a scripted companion:

Still with the console open and the runaway in the title of the console:
1. Type "StartCombat player", hit "Enter"

Close the console. If it works, your runaway will not actually attack, and will now be cured. If he does attack, my solution didn't work for you, and you should reload from your save and try other things.

That worked perfectly, thank you!
That Aldam is a fast worker. Three days to build a small mansion.