A young Carmack hard at work writing code, long before he was accused of stealing illicit copies of his own work.

Oculus CTO John Carmack was largely vindicated last week when a jury cleared him of any personal liability in a case where he was accused of exploiting trade secrets, stealing and reusing code, and destroying evidence from his time working at Id Software parent ZeniMax Media. Still, the Doom co-creator is publicly bristling at accusations aired during the trial that he made “non-literal” copies of ZeniMax code while working for Oculus.

In a lengthy public Facebook post, Carmack takes direct issue with a ZeniMax expert at the trial who said repeatedly he was “absolutely certain” that Oculus code was substantially similar to code written while Carmack was at ZeniMax. “Early on in his testimony, I wanted to stand up say ‘Sir! As a man of (computer) science, I challenge you to defend the efficacy of your methodology with data, including false positive and negative rates,'” he writes. “I just wanted to shout ‘You lie!'”

The legal issue at hand here deals with the “substantial similarity” copyright standard, where even a work that isn’t a verbatim copy can be considered infringing if “the pattern or sequence… is similar” to the original (as a 1992 federal decision put it). Carmack himself gives the example of a copied program where only the variable names were changed as a clear example of “non-literal” infringement.