Scroll casting and Test of the Smoking Eye

[Herald]

I keep reading the rule about scrolls in the DMG on p. 238. and I don't see that successfuling casting a spell from a scroll allows the scroll to stay intact on the scroll. Im refering to the passage on p. 175 of The Shackled City book. Can anyone clear this up for me? Am I reading this right?

I keep coming back to this "The writing for an activated spell disappears from the scroll."

[Talon Stormwarden]

It's referring to what happens if he fails his caster level check. If he fails his caster check but does not fail the DC 5 Wisdom check (which would indicate a mishap), then the spell remains on the scroll and he can attempt casting it again.