Palou had a healthy 5s lead over Team Penske’s Josef Newgarden going on to the final lap but came across Armstrong on the approach to The Kink – one of the fastest and most fearsome corners in American motorsports.
Armstrong – who previously tumbled down the order due to a strategy error – had gone off at the Carousel and rejoined directly in front of the race leader.
Fortunately, he was told over the radio that Palou was approaching, whereas the Spaniard had no radio communications at that part of the track, before sweeping around the outside of Armstrong.
“Honestly they couldn't tell me because from Turn 8 until Canada Corner, there's no radio,” revealed Palou.
“Well, it's very hard [to hear], so we decide not to talk on those corners to avoid misunderstandings. They couldn't really tell me.
“Suddenly I saw a car. I didn't know it was Marcus. I don't know what happened to him.
“Yeah, [it was] quite on the edge there. Honestly, having a good five-second gap allowed me to just take it easy and overtake him.”
Armstrong, on the other hand, had been warned of the potentially disastrous situation.
“It looked fairly sketchy there, but I knew he was coming,” said Armstrong, who finished 24th.
“Someone told me on the radio that Alex was obviously leading the race and to let him through, so that’s what I did.
“It wasn’t an ideal way to finish the race but it’s something I’ll look back on learn from for next time.”
Source: Autosport