Teare was 32-seconds away from making the team in the 5000. He was 3.7 seconds away from making the team in the 1500.
I have no idea why you think "If only he'd gone all in on the 5k, he would have made it."
He was clearly off his game in both races. His 5000 abomination had little to do being "tired" from the 1500 that was run a week earlier. If i was him, I'd immmediately get a full blook panel done to see if he's anemic, has Covid, or mono or something else going on as it's hard to explain how bad he was.
Both races were pretty much ideal for him - fairly fast, pseudo time-trials and he was a total non-factor. Our logic was simple, "He's unlikely to make either team so two cracks at it are better than one."
Let's say if Teare runs just the 5000 and goes all in on one event, he has a 40% chance to make it. But if he doubles he has a 25% chance in both the 1500 and 5000. The math says it's better to double as then 43.75% of the time he'd make the team (1-(.75*.75)).