[78-L] 3 Seconds of Nothing??

[78records at cdbpdx.com.invalid]

Something new and totally unexpected.  I have digitized many thousands of 78 rpm records and this is the very first time I've come across this anomaly - about the middle of the recording there is a 3 second long silence, like the recording engineer accidently flipped off the switch or something.  A close examination of the play surface shows only perfectly straight groove walls about 4 grooves wide.
I assume ordinarily, this type of foul-up would have been cause to reject a recording, but this one slipped through.  The recording is ONE SWEET LETTER by Doc Evans Band on the Dublin's label, this being one of four records in an album of Doc Evans recordings.
Here is a link to the recording:
http://78records@cdbpdx.com/DEB-a/ONE-SWEET-LETTER_Doc-Evans-Band_DUBLINS_D1b.mp3
The 'dead air' is at about 1' 44" seconds into the song.
First time for everything, I guess.
Cliff