A signal mirror enabled this rescue - but don't count on getting this lucky ...

The fisherman was rescued when the signal mirror suspended from his neck reflected light to his rescuers ... at night! (1:30 AM)

Rescuer quote: “We were under night vision goggles, looking around and we saw a flash of light from his signal mirror that he happened to have around his neck,”

The moon was 88% full that night, so the reflection off the mirror may have been the moon.

I've used a signal mirror to deliberately flash moonlight but this is the first account I recall where an accidental moon reflection was credited.

Full article here: Missing Fisherman Rescued by HSM-37 Helicopter Team in Oahu Waters

The above is the only report I found that mentioned the signal mirror, but here are other reports on the incident:

Survivor located at 1:30AM
US Navy Press Release with video
US Coast Guard News Release
Rescuer Hometown Paper Coverage
US Navy Community Outreach
USCG Bulletin when search in progress

[ UPDATE: This article mentions the mirror, and in the interview recording, the airman mentions the mirror as well:
Article with recorded interview of airman
Here's another article mentioning the mirror
Article about rescue swimmer ]