Boudjellal's comments came as French sporting experts have begun highlighting cocaine's role as a stimulant which is particularly valuable in a high-octane spectacle like rugby.
"Cocaine boosts performance by increasing alertness, reactivity and aggressiveness," Xavier Bigard, scientific adviser to the French Anti-Doping Agency (AFLD), told the AFP news agency.
Recent remarks from Christian Bagate, a former head of the French Rugby Federation medical commission, of "the Monday-Tuesday-Wednesday corticosteroid-cocaine cocktail" have gained headlines in France.
The mix is said to help a player through heavy training sessions at the start of the week and be ready for a match at the weekend. The body can quickly eliminate any trace before any weekend checks are likely.
According to Bigard, cocaine increases the heart rate but also eats into energy reserves.
"In reality, the situations where cocaine helps performance are in short burst, high-intensity efforts like in a weightlifting movement."
Experts say that in a sport like rugby, the drug could assist sudden explosive efforts, split second decision-making and help combat the effects of tough tackling.
But Bigard said using the drug is dangerous as athletes under the influence of cocaine are 20 times more likely to suffer sudden death than the average consumer. It is also addictive.
"It is a very practical product, easy and cheap to buy, for taking care of match after-effects and putting up with the heavy workload," former French rugby international Laurent Benezech, author of a controversial 2014 book on the use of drugs in rugby, told AFP.
"The barriers between the party side and the sporting are not solid. The first contact with cocaine almost certainly comes in the former."
South African-born former French international Pieter de Villiers was at the centre of a doping storm when he tested positive for cocaine and ecstasy in 2003 and was banned for bringing the game into disrepute.
Boudjellal said that O'Connor's case was "complicated", and it might affect his contract renewal negotiations.
"It's tough to defend him. We'll talk about it with him," Boudjellal told AFP. "He's a 26-year-old kid, I'm neither there to destroy him nor support him."
Boudjellal, who has brought former All Blacks like Tana Umaga and Carl Hayman to Toulon as well as originally signing Sonny Bill Williams to rugby, said French clubs had to act against the spread of cocaine.
"We've had the alcohol stage, now we're at another one. We can't support that. That needs to stop."
While several sports are involved, Bigard said rugby players are most tempted because there is no other sport with such "rising demands" linked to "a reduced recuperation time".