“I just passed my drug test. My dealer has some serious explaining to do” is a jocular line—the joke is that the “drugs” the dealer sold weren’t legit—that has been printed on many images. Authorship is unknown.
 
“I have and I passed (a mandatory drug test—ed.), which is good I guess. But my dealer has some explaining to do” was posted on the newsgroup alt.nuke.the.british on March 6, 2001. “I got the results back from my drug test at work today,they’re negative,which means my dealer has some explaining to do….” was posted on Twitter on September 12, 2009.
 
     
Google Groups: alt.nuke.the.british
The USA
twofish
3/6/01
In article <3AA3C09F…@hotmail.com>, Septic Baiter

wrote:
 
> I suppose to a citizen of a country where the employers can crap all over
their
> employees, holidays probably do seem less of an issue.  Have you had your
mandatory
> drug test this year?
>
 
I have and I passed, which is good I guess.
But my dealer has some explaining to do.
 
Twitter
colin butcher‏
@colinlr
I got the results back from my drug test at work today,they’re negative,which means my dealer has some explaining to do….
4:11 PM - 12 Sep 2009
   
Twitter
Telling Dad‏
@tellingdad
My employment drug test came back negative, which I guess is good, but my dealer has some explaining to do. #quote
11:17 PM - 30 Oct 2009
 
Twitter
Not Harry‏
@Not_Harrypotter
Had a drugs test yesterday, got the results - it came back negative! My dealer has some explaining to do.
2:32 PM - 4 Nov 2009
 
Twitter
Gonthorian‏
@theHurtbeast
So I found out today that my drug test results were NEGATIVE. Which means my dealer has some SERIOUS explaining to do.
8:18 PM - 29 Dec 2010
     
Google Books
Running with My Pants Down
By Jim Cuba
Bloomington, IN: iUniverse
2011
Pg. 54:
I was selected for a “random” drug test. Yeah . . . random my ass. It came back negative. Excellent, you say? Not so fast. My dealer has some serious explaining to do. Just kidding . . . really.
 
Twitter
Daniel Williams‏
@AK69Noob
So I found out today that my drug test results were negative. Which means my dealer has some SERIOUS explaining to do. -Peter Griffin
6:12 PM - 7 Jan 2011
   
Twitter 
Bad Girls’ Humor‏
@BadGirlsHumor
Took a drug test last week. It came back “Negative”, which means my drug dealer has some serious explaining to do.
2:12 PM - 3 Nov 2011
 
Twitter
Fresh Stand Up‏
@FreshStandUp
I just passed my drugs test!My dealer has some serious explaining to do. (via Lad Bible) http://bit.ly/1AUKLbx  via @sickipedia
5:23 AM - 21 Mar 2015
     
Reddit—Jokes
I just passed my drug test
submitted October 20, 2015 by FatherMagoo
my dealer has some explaining to do
 
Twitter
Eddie Volkman‏
@EddieVolkman
My new job gave us a surprise drug test today but mine came back negative. I think my drug dealer has some serious explaining to do…
2:25 PM - 28 Oct 2015
 
Reddit—Jokes
I had to take a drug test
submitted January 3, 2018 by eddit_ELI28
I failed with flying colors
COMMENTS
gagga_hai
I just passed my drug test
My dealer has some serious explaining to do