The 57-year-old is in court in Nice over comments he allegedly made about Ramadan and Muslim players.
According to the coach's lawyers, investigators should have set up a witness confrontation with Nice director Julien Fournier and heard from club captain Dante and its medical team.
"We are talking about harassment at all levels, and we have not heard from the captain of the team, Dante, a player who made 300 matches with OGC Nice, because it is Julien Fournier who decides," said Sebastien Schapira on Friday.
"The investigators do not know football and Julien Fournier has fooled them," added Galtier's lawyer.
The affair blew up in April following a leaked email reportedly from Fournier sent to Dave Brailsford, the former head of British Cycling and now director of sport at chemicals giant Ineos, the owners of Nice.
The email accused Galtier of making discriminatory remarks towards a section of the Nice squad.
Nice public prosecutor Damien Martinelli requested that Galtier be given a one-year suspended prison sentence and fined 45,000 euros ($49,000).
In one section of the email, Fournier mentions a conversation between himself and the coach, after Galtier had been surrounded by Nice fans in a restaurant the night before and allegedly stated that there were "too many Muslims and blacks" at the club.
In another part of the email, the director tells of an incident during Ramadan in 2022, which accuses Galtier of also claiming repeatedly there were too many Muslims at the club and of asking to have them transferred.
Prosecutor Martinelli said Galtier "clearly sought to reduce the number of black people and Muslims in the team".
"For a professional club, Ramadan is a given. For Christophe Galtier, it's a problem," Martinelli told the court.
In a further passage of the email, Galtier is accused of having described an opposition defender as "King Kong".
The former Paris Saint-Germain coach admitted this but claimed that for him the term just means "power and strength".
In April, when the allegations first appeared, Galtier issued a full denial and promised to have his say in court.
"I was brought up on a state housing estate and in a multicultural environment with shared values and respect for other people, whatever their origins, colour or religion," Galtier said.
"I cannot accept having my name tarnished in this way. I have therefore decided to take legal action against anyone who tries to damage my reputation."
Galtier left PSG in June but returned to management four months later after being appointed by Qatari side Al Duhail.
