However, Rey said his employer was being culturally colour blind as the French approach just "tends to be more direct and expressive".
Au contraire, his "direct, honest and professional personality" was, he insisted, drummed into him at French hospitality school and he was simply following their guidelines.
Grumpiness aside, both parties agreed Rey was good at his job.
The restaurant and its parent company had attempted to brush off the discrimination complain but tribunal member Devyn Cousineau denied that request, meaning it will receive a yet unscheduled hearing.
The outcome, however, is still far from certain.
"Mr Rey will have to explain what it is about his French heritage that would result in behaviour that people misinterpret as a violation of workplace standards of acceptable conduct," she wrote in her decision.
So aware are French authorities of the country's reputation for rudeness, in 2015 the tourist board launched a multi-million-euro drive to improve their "difficult relationship with service and by extension our relation to others".
In 2013, the Paris Tourist Board distributed a "politeness manual" for service industry workers. Three years earlier, the city paid "smile ambassadors" to be friendly to tourists at the city's main attractions – to little avail.