Two adult males witness a peculiar flare of light in the nighttime sky; not a flare from an Iridium satellite.

Peculiar "flare" of white light in the nighttime sky; not caused by an Iridium satellite.
Two adult males were standing and admiring the clear night sky, identifying the constellations in the northern and western sky.
 As one was looking at the Big Dipper, he suddenly noticed a very bright light, the approximate apparent size of a bright star, suddenly flare up at approximately zero degrees (true) azimuth, and at approximately 85 degrees angle of elevation above the horizontal plane.  The object was almost directly overhead of the observers' location.
 The first observer quickly called the object to the attention of the other witness, who apparently already had observed it.
 The first observer checked the time of the event with his cell telephone, and the time of the event was measured at 22:11 hrs. (Pacific Daylight Time).  He then stated to the second observer that the event probably had been caused by the reflection of sunlight from an Iridium satellite.
 However, the first observer, who has witnessed dozens of Iridium "flares," was surprised by the fact that the light appeared to be moving surprisingly slowly.  During the duration of the event (3-5 seconds), the object did not move more than from one quarter to one half degree of arc (estimated), much less than the typical angular velocity of a satellite in low Earth orbit.
 When the first observer returned home, he checked the website, , and was surprised by the fact that no "flare" from an Iridium was visible at 22:11 hrs. (local) on April 27.  The schedule of flares is seen below:  Date Local Time Intensity ( Mag) Alt.  Azimuth  Distance to flare centre Intensity at flare centre (Mag.) Satellite 26 Apr 03:34:51 -4 14° 96° (E ) 44.1 km (E) -6 Iridium 35 26 Apr 03:35:08 -4 14° 96° (E ) 40.1 km (E) -6 Iridium 36 27 Apr 03:37:54 -6 17° 98° (E ) 1.2 km (E) -6 Iridium 7 27 Apr 23:28:15 -7 24° 242° (WSW) 13.6 km (E) -7 Iridium 63   I have no idea what we witnessed.
 I am a commercial pilot, and consider myself to be more than moderately acquainted with the nighttime sky, and most of the events that traditionally can be witnessed in it.