Most systems can be hacked with force. You can also "hack" you way into a bank vault if you have 15 million tons of dynamite and an atomic bomb (not sure if there would be anything to come for in the vault at this point, though)
This is a fixable bug though. And no force of any kind was used here. As mentioned other trains use the same lever design, but with the lever being spring-returned, which doesn't exhibit this 'vulnerability'. It could also just be fixed in software by making the lock lever input to the microcontroller edge-triggered instead of level-triggered, so that if someone does actually do this it won't lead to a DoS.