Q 095

(accidentally posted earlier in PF Simple Q&A)

Can you use Shadow Cloak (DotU) (or similar abilities) after you know you've been hit but before you know damage? Or after you fail a save but before you know what bad stuff happens?

For example, someone hurls a Lightning Bolt at you. You want to teleport out of the "line." Do you have to do it before the reflex save, or can you do it after making the roll but before damage?