I have another one. I've been working on this page of actors who have appeared in multiple roles, and I am skimming through all the MacGyver episodes to capture images (while SG-1 is playing on Comet TV at the same time - talk about a time warp!)
Anyway, I got to Blow Out, and the two hoods who rob the grocery store are Steve Blalock and Vince Deadrick, but they are wearing hockey masks, so it's a challenge trying to figure out which is which. The only clue is eye color, and that remined me of another story:
Two of the SG-1 actors who appeared in multiple roles, often with a lot of makeup, are Dion Johnstone and Alex Zahara. Occasionally they appeared in the same episodes. RDA told a story about one day on the set with a lot of Unas. Dion and Alex were both made up as an Unas, and while they don't look identical, the only real clue about who is who is eye color. Dion is black, with dark eyes, and Alex is blond with blue eyes. RDA said he once had an entire conversation on the set with one of them, and didn't realize until after he walked away that he was actually talking to the "wrong" one.
This actually reminds me of another story. I learned to fist-bump from Dion and Alex. This was years ago when fist bumping was just becoming a thing. I had already met Alex, and I was introduced to Dion, both of whom were made up as an Unas. Dion held out a fist in greeting, and I thought he was just doing that because shaking hands was more difficult with claws. So I reached out to take his hand, and Alex explained that I should make a fist instead to bump against his. So I can honestly say that I learned how to fist bump from two Unases.