The player might likely also face legal actions in Columbia and/or Ecuador over forging of documents which is crime in any country, but it's still going to be the country's FA fault for fielding an ineligible player, and it doesn't matter whether or not they were aware of the situation, it's going to be a case of ignorance not being an excuse, I remember a case of Real Madrid being kicked out of Copa Del Rey some years after field an ineligible player "Dennis Cheryshev" in that year, he was supposed to serve a one match ban while being on-loan at Villarreal the season before, and meanwhile Real Madrid claimed they weren't aware of the players suspension, but that still wasn't enough as excuse to overturn to decision from the governing body.
I don't agree with you. If the player managed to hide his ineligibility, how it is going to be the association's fault? And what FIFA is doing is certainly abuse of power. In case of Denis Cheryshev, it was his fault that he didn't informed about his suspension to the new club. And instead of punishing the player, the association decided to punish the club. This is similar to national teams getting punished whenever someone does hooliganism in their home matches. Actions of one or two people can't be used to punish an entire team.
I agree with you that the decision can be argued to be unfair, but unlike the olympics where most of the sports are individual where a culprit can be stripped of a medal, but if it's like a basketball team player that's found doping even after several years, it's the entire team that pays the price and get stripped of their medals, but what do you think should happen ? For instance in the case of Real Madrid where Cheryshev I think even scored in that match. You really just can't void that specific goal or all his part from the entire match that has been concluded. It's always the team's responsibility that all players that are being fielded are eligible and it's FIFA responsibility to them verify these stuffs are accurate, hence the stiff penalties, I'm sure sometimes the players also get individual penalties, but how will FIFA get to know that teams/countries aren't aware of those findings but just choose to ignore simply because they're not to be affected if the truth gets out.