Myth #25 - No run can score when a runner is called out for the third out for not tagging up
Yes it can. A tag up is not a force play. A force play is when a runner is forced to advance because the batter became a runner. When the batter is out on a caught fly, all forces are removed. An out, on a failure to tag-up, is NOT a force out. Any runs, that cross the plate before this out, will count.
LL Playing Rules: 2.00 Definition of Terms: FORCE PLAY, 4.09 Approved Ruling, 7.10(a)