Before continuing Your accusations, please provide GPL license text that is violated when sending binaries over private channels. You can assume that user is asking and paying developer to make better code for him from open source code. Can You make citation from GPL license that is broken with this?
Oh yeah? He's making better open source code, so he can then open source it? Using a loophole doesn't make it right. You're not supposed to be able to profit off other persons open work without their permission, that's the way it works. Just because you do it in private doesn't mean you aren't violating it. It's like doing something illegal profit still makes it illegal even if you more then likely wont get caught.
Your freewill understanding of GPL license doesn't count at all. If You can not provide citation of GPL license that is broken with before mentioned case than You should stop Your false accusations.