Earned Run or Not

Maybe, maybe not. Assuming it was officially scored a double, it will only be unearned if that extra base (third) comes into play.

For instance, if the next 2 or 3 guys come up and get base hits scoring the run, it is earned. If the next guy hits a sac fly, and the next guy K's I believe that would be unearned because the run wouldn't have scored without that extra base caused by the error.

Too much missing info: Sounds like the first guy is a 2B with an E to third. If he was still on second, would he have scored before three outs with no errors that would have been outs????

Welcome heater34. Very simple to determine if you look at the score book but impossible if you don’t. It depends on how the official scorekeeper scored the play. The way you describe the play defies description in the rule book. There is no way to describe a “squiggler down the line” or a method to describe a player getting to the ball “late”. It is either a triple with no error, or double and a subsequent advance to third on an error by the left fielder ---- but even if it were scored a double with an error it can still be an EARNED run. The only way to make this run qualify as an Unearned run is to 1. Give an error to the lf on his advance to third and/or have other errors prior to (or after) the double (or triple) AND then reconstruct the inning WITHOUT that error or any other errors. ONLY after the inning is over can you reconstructing the inning (without errors) and determine if the runner would have scored or failed to score with errorless play. People (pitchers or parents of pitchers) want to know in black and white if the run is earned or unearned and it simply cannot be done in most cases until the inning is over and the inning reconstructed without errors.
Fungo