Here is my card's text:
"When this creature is destroyed, you may pay its casting cost. If you do, summon it into the zone in which it was destroyed after the current action resolves."
Here is the version in the spellbookbuilder:
"When this creature is destroyed you may reveal Second Chance. You may immediately summon this creature into the zone in which it was destroyed as a free action."
There is nothing in the current version of the Rules Supplement about this change. And certainly my card's wording, as with werner's, suggests that it needs to be revealed before the killing blow destroys the creature.