the Logitech F710 is a solid controller to get if you’re on a tight budget, but perhaps not exactly the type of equipment you want to stake your life on. […] Reviewers on sites like Amazon frequently mention issues with the wireless device’s connection.
The reporter, who followed an expedition of the Titan from the launch ship, wrote that “it seems like this submersible has elements of MacGyver jerry-riggedness.”
That or lost connection/battery.
The only wireless controller I ever owned would continue any repeating input active when connection dropped, if batteries or wifi died; they could just be cruising at max speed off in whatever direction they were facing, until the motor batteries run dry.
You’d like to think they’d carry backup interface, or even just use a wired controller, but this whole op sounds pretty McGuyver top to bottom.