Maybe a nw.js issue then? If you can reproduce it reliably then filing a bug with scirra is your best bet. As an alternate to nwjs they have that webview2 export which seems to have less issues. Maybe that's a solution.
I made a video to demonstrate it better. If you notice, out of nowhere, the camera goes all Exorcist, as if it's twisting the player's 'neck' upwards or sideways. THIS HAPPENS WITH ANY CONSTRUCT EXAMPLE, and the funniest thing is that it only occurs on one of my computers, not the other.