Didn't one of the warehouse guys just make that up to satisfy Michael's need to hear some "authentic" street talk?

Hahaha...it's actually DINK n' Flicka...and yes Darryl played a little prank on Michael because he wanted to learn some hip urban terms. Hence the smirk on his face when Michael says it to him. :)

Sorry to burst your bubble sfdude, but it turns out it's a real term used "dinkin flicka" from the urban dictionary:

dinkin flicka:

Made popular in a recent episode of "The Office", dinkin flicka roughly translates to "That's life" or "C'est la vie".

It can be used in many circumstances and basically means, 'well, what can you do about it?.. that's life'
The expression is generally used in response to horrible circumstances and is often repeated in agreement by the one in the bad situation.

According to the Office, the expression is "something us Negroes say" but dinkin flicka has recently gained popularity among other ethnic groups.

Darryl: I grew up in the hood.
Michael: dinkin flicka.
Darryl: dinkin flicka.

I just got shot!
dinkin flicka...
yea.. dinkin flicka...

omg...great scene. personal favorite: fleese it out.