Aaron Phypers was shocked as he was arrested Friday for alleged domestic violence against Denise Richards … ’cause he says the last time he spoke to cops, he was reporting HER for similar allegations.

Michael Finley, Aaron’s lawyer, tells TMZ … Aaron wasn’t interviewed by authorities prior to having cuffs slapped on him on a felony arrest warrant connected to allegations Denise leveled from 2022.

TMZ broke the story … Aaron was arrested at the courthouse during a restraining order hearing with Denise … and subsequently charged with 2 felony counts of injuring a spouse and 2 felony counts of dissuading a witness by force or threat.

As we previously reported … Aaron filed a report against Denise with the L.A. County Sheriff’s Department over the summer for alleged vandalism, theft and assault related to the July 4th fight after filing for divorce. We’re told they never reached out about Denise’s allegations.

Finley finds the Friday situation outrageous … but tells us Aaron didn’t need to be interviewed before a warrant was issued if a judge determined there was probable cause.

Aaron was sprung from the joint super quick … Finley tells us, “people who care about him” ponied up the necessary funds to satisfy the $200,000 bail — meaning he was only in custody a few hours.

We’re told Aaron’s in “good spirits, and all things considered, has a good attitude” about the situation … ’cause he vehemently denies the accusations, and he’s ready to fight the charges.

Finley tells TMZ … he will remain Aaron’s divorce lawyer and help him retain a criminal defense attorney.