Default is to not call what you cannot see. That way in all sports. Don't anticipate. Don't assume. Don't "think" what may have happened. See or not see. And yes, the default (presumption) should be that it was a HR until reviewed and declared otherwise. If a tie goes to the runner, doesn't that reward the offense? Yes it does. And that's baseball. The defense has such an overwhelming statistical advantage that it has been and should be this way. If a football official "thinks" a player is down, should he blow the whistle? No he should not.
But Joe West is saying he saw it... That is why he made that call...
https://weei.radio.com/blogs/rob-br...versial-call-taking-away-jose-altuve-home-run