How does ignoring the first retreat flag work?

Question

In Memoir '44, if an infantry unit is surrounded by sandbags, the rules state that the unit "may ignore the first flag rolled against it." I can come up with two interpretations that seem to have very different implications of the power of a sandbagged unit:

1. In order to force a retreat you must roll two flags during one attack (e.g., roll two dice, get two flags, the unit retreats). Sandbagged units are nearly impossible to force a retreat without resorting to using certain tactic cards.

2. You can roll one flag on one turn, then on a subsequent turn you may roll another (single) flag, and this forces the sandbagged unit to retreat. Sandbagged units are still difficult to force away, but not nearly as bad as (1).

What is the correct interpretation?

Answer 1

Quite literally, ignoring the first flag means that flag is a "no effect." It is measured per roll.

So, in order to force a retreat, an a sandbagged unit or unit in a bunker that ignores a flag must have two or more flags rolled against it in order to force its retreat (or additional hits if it can't retreat).

Support for this view is in Richard Borg's FAQ dated 4/15/05

Q. For artillery in bunkers, flags are treated as a hit. Do they still ignore the first flag?

A. Yes, Bunkers (page 16) Basically an artillery unit in a bunker may not retreat. Therefore it must lose one figure for each retreat move that cannot be completed. But like all other units in a bunker hex, it may ignore the first flag rolled against it. In other words, it takes two flags to make one hit, and three flags to make two hits.

Note that the bunker allows ignoring the first flag... but artillery can not retreat from a bunker, so flags on bunkered arty are hits, not retreats.