Sorry- if it’s a remote opportunity he can.
OH! Ok now we're getting somewhere. See, here's his situation. He was offered an opportunity in 2014 to move to the US (Pittsburgh) to work for a company there. We did the whole US visa process which took 2.5 years... in that time the political situation there changed and the company moved to Texas. We decided we no longer wanted to go to the US but the company didn't have an office over here. So they constructed it that he start his own company and bill them as a contractor, working remotely from Europe. So he works for them but just sorts out his own local social security, taxes and all that.
When we moved from the Netherlands to France 2.5 years ago, for tax purposes he had to close his Dutch business and open a French one.
When we get to Canada and he gets his residence permit, he will then close his French one and open a Canadian business to start paying taxes there and generally being a contributing member to society.
So, if we were to go to Canada with him as a visitor, he could work for that 3-4 months for the US company, via his own French company ... but the open work permit gives him the ability to work, but without his residence permit, it wouldn't allow him to open a company, would it? I can't imagine that would be possible until he's been approved to stay?