Yes, they CAN just spin off if they’re not properly torqued. I had it happen with a set of aftermarket upper control arms that came with the ball joints already installed. Took it in for an alignment after the install, shop wouldn’t do the alignment because one of the ball joints was moving and wouldn’t hold an alignment. While sorting it out I discovered that neither of them had been properly torqued even though they both looked fine during the install. The other one was still “tight”, but not anywhere near 125 ft/lbs. I’d only driven the car a handful of miles and the other had already loosened.
Sorry, but installing them with channel locks is just flat out stupid.