The solicitors worked with Yirrkala Aboriginal Community, who sued Sunrise in 2019.
Mr Flowers said he was suing because he wanted media outlets to do their jobs “more seriously and professionally.”
According to defamation lawyers, Mr Flowers could sue for more than $400,000.
Barrister David Gilbertson, QC, whose areas of practice include media and defamation law, said the mistake could potentially cause problems for Seven West.
The actual alleged offender has now officially been identified by police as Carnarvon man Terence Darrell Kelly, 36.
On Thursday, Mr Kelly was charged with child abduction and appeared before Carnarvon Magistrates Court.
WA Police Detective Senior Sergeant Cameron Blaine said Cleo was found in physically good health in a bedroom inside Mr Kelly’s house.
“The lights were on and she was playing with toys, I think that’s about all I want to say. This is still a matter that needs to go before the courts. There’s certain aspects about what we saw that is going to be evidence,” he said.
Detectives declined to comment on whether dolls were found inside the house, with the head of Taskforce Rodia, Superintendent Rod Wilde, telling journalists he “didn’t want to go into that”.
Since his arrest, video has emerged of Mr Kelly recording himself inside a room filled with dozens of dolls, some still in their packaging.
The man also uploaded photos to Facebook in April 2020 taking a doll for a car drive, captioning the post, “I love taking my dolls for drive arounds and doing their hair and taking selfies in public”.
In another post dated July 2020, Mr Kelly is pictured wearing a Bratz doll shirt and holding a doll in each hand, commenting: “Nothing beats chilling at home with by Bratz dolls.”
More than 140 police officers were assigned to Cleo’s case, with 63 working full time out of Carnarvon.