Pretty much. The energy required to split water into hydrogen and oxygen can NEVER exceed the energy obtained from burning that same hydrogen and oxygen. Since electrical wires have resistance, and motors aren't 100 percent efficient, you can never get out as much energy as you put in. Otherwise, you would have a perpetual motion machine.
These things always seem like such awful snake oil. Even if there was an evil US conspiracy to keep something like this away, they'd just produce it somewhere that doesn't care and ship it here like we do with all sorts of other patented ideas.
Europe has miraculously managed to have safe small vehicles that get from 40 - 55+ mpg without hybrid tech. Our only real issue seems to be that we don't embrace smaller vehicles like this or embrace alternate vehicles like motorized bikes and scooters.