Chad Johnson patted his lawyer's ass in court Monday as a sign of respect ... so claims the tapee, attorney Adam Swickle.
Swickle filed legal docs -- just obtained by TMZ -- in which he pleads with the judge to reconsider her decision to throw out Chad's plea deal and throw him in the slammer for 30 days -- all because she believed the former NFLer disrespected the court with the tap.
In the legal docs, Chad's lawyer says "Mr. Johnson has been a professional football player in the National Football League for eleven (11) years and patting another individual on the backside is viewed as a sign of respect and gratitude."
Swickle also noted that Chad was goaded into finding some form of compliment by the judge herself, who told him to thank his lawyer.
As for the judge's outrage that people in the court were laughing at the ass tap ... Swickle says, "This is not Mr. Johnson's fault and he should not be punished for the actions of third parties."
Swickle says the 30-day jail sentence is "somewhat excessive" and is asking the judge to reconsider. A hearing is set for Monday. Until then ... it's pokey time for Chad.