Very hard to prove any collusion. It wasn't as if anyone scored an own goal or deliberately dropped the ball into their own net, or stood back and let the other team score.
Desperate times need desperate measures. Chilean angst is not surprising as their management now tries to deflect the blame on to "collusion" when the collective ire of the nation hits home over them missing out. Snowflake's chance.
Chile have been an awesome team year in year out (think "Bielsa"), and you say they did not qualify "against expectations". It is a killer of a group, CONMEBOL.