Official Scorer Ruling

Marlins/Nats 5th inning 2 runners on base with 2 out,  next batter hits grounder to second baseman and he flubs the throw so now bases loaded 2 out. Next batter singles 2 runs in to score but official scorer so far rules those batters wouldnt have scored due to second basemans error.  Is this typical?  seems guy who reached on error could be an unearned run but the 2 guys who had base hits?  Seems sketchey.  Anybody know the rules here? 

The inning would have ended without the error......every run scored after that is unearned......there was a game the other day where like 8 runs scored that were unearned....even if pitcher gives up several hits in a row..all the runs are unearned after an error happens during inning that extends the inning....or even if it happens with one out and pitcher gets next out...which should have ended inning.....any runs that come in after that would be unearned too.

Ok seems plausible but I thought Ive seen runs counted as earned even with errors committed, maybe I'm wrong here.  Thanks for explanation. 

@McXmaster

 If the 2nd baseman doesn't make an error and the runner is out at first, nobody scores. That's why they're unearned.