Discrepancy

If I had to use the word "discrepancy", I would say "there was a discrepancy in the materials [reported]".

I think the word "discrepancy" doesn't fit perfectly here and might say "they disagreed on what was in the bottle" or something more like that.

Or, alternatively (continuing with what Rich has posted), "there was a discrepancy between the reports."

Google hits:
"Discrepancy between" - 273,000
"Discrepancy in" - 158,000
"Discrepancy of" - 42,000

According to the usage I've sampled:

"Discrepancy between" seems to be used to compare two things that should be the same but are not: "There were discrepancies between the proof copy and the submitted manuscript."

"Discrepancy in" seems to be used when talking about one thing that just doesn't fit the known facts: "There were some discrepancies in the story she told the police."

"Discrepancy of" seems to be used in the special case of tolerances or variation from standard measurements: "There was a discrepancy of 4.28mm in the inside diameter of the well bore." "Discrepancies in the test results averaged .02 percent of the expected value." (The second example is a "discrepancy of" with an intervening prepositional phrase.)

Could use a preview mode on this thing....

"...intervening prepositional phrase..." was a really stupid thing to say, sorry about that. You should still see that "discrepancy of" in that last example.