“The only time a fisherman ever tells the truth is when he calls another fisherman a liar”

A liar can tell the truth when he/she calls out another liar.
 
“A contributor writes to inquire if I’ve heard this one: ‘The only time a golfer tells the truth is when he calls another golfer a liar’” was printed in the Pittsburgh (PA) Post on January 11, 1925.
 
“About the only time a Lakin fisherman ever tells the truth is when he calls another fisherman a liar” was printed in the Kearny County Advocate (Lakin, KS) on April 17, 1925. “About the only time a fisherman ever tells the truth is when he calls another fisherman a liar” was printed in the Marshall (TX) Messenger on April 24, 1925.
 
“OLD EARL SAYS: The Only Time A Hunter Tells The Truth Is When e Calls Another Hunter A Liar” was printed in the Tucson (AZ) Daily Citizen on November 9, 1963. “‘The only time a hunter tells the truth is when he calls another hunter a liar.’—Pic Larmour” was printed in the Courier-Post (Camden, NJ) on November 19, 1963.
 
“The only time a politician tells the truth is when he calls another politician a liar” was printed in the Journal Star (Peoria, IL) on July 14, 1994. “TO borrow the words from an old song about fishermen, ‘The only time a politician tells the truth is when he calls another one a liar’” was printed in The Courier-Mail (Brisbane, Queensland) on August 31, 2001. “The only time a politician tells the truth is when speaking about their opponents” was posted on Twitter by Sal the Agorist on May 4, 2020.
 
       
Newspapers.com
11 January 1925, Pittsburgh (PA) Post, “Golf and Other Troubles” by Barrie Payne, sec. 2, pg. 2, col. 6:
A contributor writes to inquire if I’ve heard this one: “The only time a golfer tells the truth is when he calls another golfer a liar.” 
 
Newspapers.com
25 January 1925, Los Angeles (CA) Times, “Bobby Jones Breaks a Hundred” by Barrie Payne, Sunday Magazine, pg. 19, col. 3:
A contributor writes to inquire if I’ve heard this one: “The only time a golfer tells the truth is when he calls another golfer a liar.” 
 
Newspapers.com
17 April 1925, Kearny County Advocate (Lakin, KS), pg. 1, col. 2:
About the only time a Lakin fisherman ever tells the truth is when he calls another fisherman a liar.
 
Newspapers.com
24 April 1925, Marshall (TX) Messenger, pg. 4, col. 1:
About the only time a fisherman ever tells the truth is when he calls another fisherman a liar.
 
Newspapers.com
24 April 1925, The Democrat-Argus (Caruthersville, MO), pg. 4, col. 4:
About the only time a Caruthersville fisherman ever tells the truth is when he calls another fisherman a liar.
 
Newspapers.com
9 November 1963, Tucson (AZ) Daily Citizen, pg. 62, col. 1 ad:
OLD EARL SAYS: The Only Time A Hunter Tells The Truth Is When e Calls Another Hunter A Liar.
(Upham Nurseries.—ed.)
   
Newspapers.com
19 November 1963, Courier-Post (Camden, NJ), “It Happened Last Night” by Earl Wilson, pg. 30, col. 3:
EARL’S PEARLS: “The only time a hunter tells the truth is when he calls another hunter a liar.”—Pic Larmour.
 
Google Books
Strictly for Laughs
By Joey Adams
New York, NY: A & W Publishers
1981      
Pg. 47:
The only time a golfer tells the truth is when he calls another golfer a liar
 
14 July 1994, Journal Star (Peoria, IL), “Booger never gets a break” by Royce Elliott, pg. C9:
The only time a politician tells the truth is when he calls another politician a liar. 
   
Google Books
20,000 Quips & Quotes
By Evan Esar
New York, NY: Barnes & Noble Books
1995, ©1968
Pg. 311:
The only time a fisherman tells the truth is when he calls another fisherman a liar.
 
Google Groups: alt.fan.mark-brian
MAD Quotes (Was Re: Another Mark&Brian racist remark)
Dave Marron
8/10/00
(...)
“These days, it seems the only time a politician tells the truth is when he calls his opponant a liar!”
- Alfred E. Neuman
 
Newspapers.com
13 October 2000, Marshall (TX) News Messenger, “Speak Out!,” pg. 2A, col. 4:
THE ONLY TIME A politician tells the truth is wen e calls another politician a liar.
     
31 August 2001, The Courier-Mail (Brisbane, Queensland), “First With The News Edition,” pg. 16:
TO borrow the words from an old song about fishermen, “The only time a politician tells the truth is when he calls another one a liar.”—Brian Rea, Ingham.
   
13 December 2003, The Courier-Mail (Brisbane, Queensland), “Letters,” pg. 26:
FOR heaven’s sake, stop knocking Peter Beattie. I thought it was common knowledge that the only time a politician tells the truth is when he calls another politician a liar and a hypocrite. As a politician, Beattie is incredible. He has made Queensland the Smart State. Thanks to his efforts on our behalf, we are all smarting one way or another, aren’t we? So let us give credit where credit’s due.- - G. R. Arnold, Banksia Beach.
 
Newspapers.com
15 February 2004, The Missoulian (Missoula, MT), “Letters,” pg. B5, col. 2:
My grandfather once said, “The only time a politician tells the truth is when he calls another politician a liar.”
Jeff Steele,
34 Grizzly Drive, Seeley Lake

 
Twitter
Darrell Sorenson
@sorensond
About the only time a politician tells the truth is when they are calling each other a liar.
9:44 PM · Mar 18, 2010·Twitter Web Client
 
Twitter
Gerald Williams Jr
@GeMacWil
“The only time a politician tells the truth is when they call another one a liar.”- Alfred E. Neuman #can’ttrustpoliticians
8:06 PM · May 16, 2011·Twitter Web Client
 
Twitter
Ram Gopal Varma
@RGVzoomin
The only time a politician tells the truth is when he says that the other politician is a liar
9:38 AM · Dec 13, 2016·Twitter for iPhone
 
Twitter
Tony Blackburn
@tonyblackburn
These days the only time a politician tells the truth is when he calls another politician a liar !!
3:58 PM · Nov 1, 2018·Twitter Web Client
 
Twitter
Sal the Agorist
@SallyMayweather
The only time a politician tells the truth is when speaking about their opponents.
2:51 PM · May 4, 2020·Twitter for iPhone