With 45 minutes on the clock, Reid rumbled over from a range more appropriately measured in feet, or just possibly inches, to claim the score that, with Finn Russell's subsequent conversion, put Glasgow 16-7 up, a buffer that would prove vital in the dying minutes of a game that saw the Irish side cut the gap to 16-15 before time ran out on them. As a consequence, the Warriors are now on the cusp of a kind of glory that no Scottish team have experienced in rugby's professional era.
Yet if Reid's try was no act of athletic grace or distance running, it is worth seeking out the YouTube footage of the score he claimed two weeks earlier in Glasgow's 38-16 bonus-point win over Treviso in the Stadio Monigo. From just outside the Italians' 22, the 19st forward produced an improbable burst of pace, deftly handing off two Treviso defenders on his bullocking charge to the left corner.
In light of which, it is small wonder that Reid, 27, is now on the verge of a Test debut as well, having been called into the Scotland squad for next month's tour to the USA, Canada, Argentina and South Africa. With no Ryan Grant or Ally Dickinson on the north American leg of the trip, it is hard to see how the former Ayr stalwart could avoid getting a cap, but his experience on last year's tour to South Africa, when he was the only player not to be used, has taught him to take nothing for granted.
Yet that venture also hardened Reid's determination to get into the Test arena, a fire that has burned within him for as long as he can remember. He represented Scotland at various age-grade levels, but missed out on the fast-track at the vital juncture when academy contracts were being handed out. That he is in the frame at all today is a glowing tribute to his unquenchable resolve.
"I was one of the hardcore boys," Reid says. "I got a job when I was 16 and I played for Ayr. It's all about game time and I just kept going. I stuck in because I love playing rugby. I just love being out there. Finn Russell [the Glasgow fly-half] often says he's not confident off the pitch but he's a totally different person when he gets out there, and it's just the same with me.
"As soon as I step on the park I forget about everything else, how hard the job might be, falling out with the missus the night before, everything. It all just goes out the window. It's like being a different person and I love going out there and playing well. It is a dream to get paid for something you love doing."
Reid did not actually start against Munster, instead coming on for Grant after 26 minutes. That pecking order might be maintained at the start of Saturday's winner-takes-all clash in the RDS, but there are question marks against Grant's fitness. Yet a scenario that might have been a disaster for Glasgow a year ago is unlikely to cause any great anxiety to coach Gregor Townsend, given the rapid progress Reid has made in the intervening time.
Prop forwards have a habit of flowering late, and Reid's career trajectory is not exactly unusual. What does distinguish him is his appreciation of his lot, a view forged in the days when he was a rugby outsider, slogging away unnoticed in the hope that, someday, his abilities would attract attention. He actually ran his own French polishing and antiques restoration business for a while before former Warriors coach Sean Lineen offered him a contract at Glasgow four years ago. Trade was good, but not so good that he was ever going to spend too long thinking about it.
"Obviously you have to weigh things up, should I continue my business or go to rugby?" he says. "It wasn't really a hard decision, but you still have to think about it. You have to give it a shot. You might not be here tomorrow. You only get one life and you have to do things you love doing, so I picked the rugby and went from there."
So he put his old life behind him? Not exactly. In the heady whirl of the past few months, those tougher times have never been forgotten.
"I've done it all," says Reid. "I've worked in bars, I've worked in B&Q, I've worked in shops. You name it, I've done it. I've done labouring, I've done roofing. I would never do roofing again because I broke just about every tile I stood on. I tried everything, but everything I did was trying to push me towards rugby.
"You need money to pay your rent and get food, to keep eating correctly and to pay your petrol to get to games. That's what I did. I'd work from eight to five or six, maybe do overtime, sometimes go home at nine o'clock at night and then have to go to rugby after it. You're absolutely knackered, but you still do it because you love it. It does put things into perspective, thinking about where you were before and where you are now.
"You never forget where you come from. I'll never forget all the people who have helped me and all the places where I've worked. It does kind of give you a kick up the arse sometimes. When I'm wondering why I'm raging about training, being out in the pissing rain, it's good to think, well, it could be worse. I could be getting minimum wage to work behind a bar."
In his approach, there is something about Reid that seems to embody the redoubtable spirit of this Glasgow side. With home advantage on their side, Leinster will start the final as overwhelming favourites, but will they go into the game with the surging confidence that Glasgow have mustered on the nine-game winning streak that brought them to this point?
Reid says: "All the boys were buzzing after the Munster game, and they are still buzzing. It is just a really good atmosphere to be in. Just speaking to the boys on the phone, there is just a big buzz about the club right now.
"We are definitely confident. Everyone is going to say we are the underdogs, but I love being an underdog. I love it when people try to write you off. It takes all the pressure off you and you just have to do your job, go out there and play your game."
The approach has served him well this season. Let's see if it can help him over the final hurdle.