However, the court ruled that given that his number was provided as one of the directors to call should problems arise, that amounted to him being "on call", and he should be paid for his time.
Under the so-called El Khomri law, named after a former French labour minister, companies are obliged to negotiate with employees to agree on their rights to switch off and ways they can reduce the intrusion of work into their private lives.
If a deal cannot be reached, the company must publish a charter that makes explicit the demands on employees out-of-hours, as well as their rights.
The French measure was intended as a response to the so-called "always-on" work culture that has led to a surge in usually unpaid overtime, and in some cases burnout, while also giving employees flexibility to work from outside the office.
Even before the 2016 measure, French law recognised a contractual right to disconnect for employees working from home.
With the new law, however, the right to disconnect has been expanded to all employees who use digital and telecommunication tools in their professional life.
Sylvain Niel, a legal expert, said that the simple fact of being "connected" outside work hours was enough to be considered "on call".
"The court's ruling reminds companies that a violation of rest time via a compulsory duty, even digital, is tantamount to being on call and must be compensated," he told Le Figaro.
A study published by Eleas, a French research group, showed that more than a third of workers used their devices to do work out of hours every day.