The FIA decided on Wednesday Mercedes should face an International Tribunal after seemingly contravening the sporting regulations.
The hearing has been called after Red Bull and Ferrari protested Mercedes' use of a 2013 car to assist Pirelli in a 1,000-kilometre test, predominantly of next year's tyres, in Barcelona in mid-May.
Should Mercedes be found guilty, a range of penalties is open to the tribunal, with the smart money at present being a points deduction.
Speaking ahead of Sunday's Canadian Grand Prix, Boullier was content the matter was being pursued.
"It's good to have a hearing, parties talking officially, and then we will see the outcome of this," said Boullier.
"But there is clearly a breach somewhere, and then you expect to see a sanction.
"Fundamentally for me there is a big issue, which is a breach of the sporting code. Testing is banned.
"You have a sporting code and a testing agreement signed by all the teams.
"Clearly, testing today is key in some way. Limited mileage forces you to change the process you design your car, the way you race.
"For many years performance was just aero, aero, aero, aero.
"Now, you still need aero, but for the first time you need to consider the management of the tyres to make your weekend a success.
"So by doing testing you have a serious gain of the understanding of the tyres, and that's something which is not fair."
After it was discovered Ferrari also conducted a test with Pirelli after the Bahrain GP and ahead of Fernando Alonso's victory in Spain, they were initially asked to assist in the FIA's investigation.
Ferrari, however, have been let off the hook as they complied with the regulations by using a 2011 car.
Boullier has no qualms with the FIA decision, although he feels Ferrari pushed the envelope, and has questioned Pirelli on equality.
"Ferrari are not in breach. They respected the regulation, and if you do that, then fine," added Boullier.
"With Pirelli it's different because they are supposed to be fair and treat everybody equally, which is borderline with their contractual agreement."
Suggested to Boullier Ferrari will have gained some data despite using a two-year-old car, he said: "They will know perfectly their 2011 car.
"So by extrapolating and comparing data you get some knowledge of the tyres, definitely, which is why I'm saying we are borderline on fairness."
Boullier feels once the issue with Mercedes has been resolved, the teams will have to sit down with Pirelli and discuss a way forward.
"We can still trust them, but we maybe have to sit down again and remind everybody of their needs of the agreement," said Boullier.
Watch Free Live Streaming From a Different Angle on Racemate LIVE