Everyone had a good laugh at HBO Max this week when the new 4K Mad Men remaster debuted with a number of glaring errors that should have been caught before the show was uploaded to the streamer’s servers. Episodes went live with incorrect titles, and in one instance you could still see members of the show’s production crew who shouldn’t have been visible on-camera. The mistakes were reportedly the result of Lionsgate Television — Mad Men’s original production company — sending over the incorrect set of exported files.

It is wild to think that no one at HBO noticed that the remastered “Red in the Face” episode still included a clear shot of Mad Men special effects foreman Shannon Thompson. When I recently spoke with Thompson — whose past credits include The Mask, From Dusk Till Dawn, American History X, Dune: Part One, and the new Matlock reboot — he told me that he hasn’t had time to check out HBO’s remaster. But he still remembers shooting that episode of Mad Men clearly, and sees it as a solid example of how much invisible special effects work goes into making mundane TV feel real.

How did you get into special effects work?

I’ve always known that I liked doing creative, mechanical things like pyrotechnics and stuff like that, so, I started working in props, and sometimes there’s cross over with that and special effects. I ended up meeting these two effects guys and immediately got along with them. They pulled me in, and I’ve been doing this for 33 years now.

Looking at your IMDb, you’ve worked on so many big sci-fi and fantasy projects, what kind of special effects work did you do on Mad Men?

For a show like Mad Men, it’s a lot of atmospheric effects. Anytime there’s something like snow or steam or rain — anything that moves on camera, but isn’t being moved by an actor — that’s special effects. Basically every elevator door you see in that show is fake, and I think the majority of my job on that show was elevator doors. I’m literally hiding in the walls, waiting for a cue, and figuring out the trick of making those mundane things seem mundane.

What all goes into creating juicy projectile vomit that looks believable and not too ridiculous?

[laughing] Honestly, you spend a lot of time studying and researching the real thing. I had to watch a lot of videos of people vomiting, but then there was the process of testing out how to make that effect, practically. We have this thing called a pressure pot that we fill up whatever liquid they want the vomit to look like in the final shot. You study how that liquid comes out of the hose normally. But then sometimes you have to manipulate the opening on the hose to make the liquid look like it’s actually coming out of someone’s mouth.

If you just have a straight tube, it’ll look like it’s coming out of a tube, so you have to change it and consider what’s in a person’s mouth normally like the teeth and uvula that makes a believable vomiting shape. And then the director will tell you what consistency they want, and you have to ask stuff like, “well, what were they eating? Why are they sick? Is it because they’re drunk or because, they have a virus?”

For “Red in the Face,” do you remember what kinds of conversations you had about the vomit’s consistency?

For that, they actually wanted Roger Sterling to have been eating oysters, and [producer] Matt Weiner was like “it needs to be clam chowder-ish.” So…I wound up using clam chowder, and figuring out how to get it spewing everywhere.

What do you think might have gone wrong in the remastering process that led to you being left in the shot that everyone has seen now?

I guess just not knowing what the future held, you know? Every time we did an effect, we needed to be as close as possible while being just out of the frame.

When you were originally shooting this, was the assumption that you would just be cropped out?

Yeah. Back then, we always tried to camouflage ourselves as much as possible, but these days they tend to just say “we’ll erase it in post.” Only this time, apparently they didn’t erase us.