So the REG contradicts itself? Sean's quote says you CAN'T reenter battle on the same turn, and MJB's quote says you may?
I always thought that the Special Conditions/Clarifications section took precedence over what was written in the General Description section of the REG. Especially in this case, where The Long Day is singled out with a specific ruling.
Do we know how the characters returning to battle rule was originally meant to apply to The Long Day?