True, although in fairness it's a fairly weak beta emitter. The 100,000 picocuries of Potassium-40 your body has emits betas that are about 120 times more energetic, or sometimes emits gamma rays instead.

Probably better to not get exposed to tritium all other things being equal but you would receive more damage from radioactivity IMO inhaling someone's cigarette smoke. I suppose this depends on exactly how much tritium is present in the steam that was vented.

The original engineer also left out the many other radionuclides that are created that don't break down instantly, but his points about filtering most contaminants out before they are vented, and their destination of the vast Pacific Ocean is right on target.

Tritium betas are about 0.005 MeV, not 1.000, and can penetrate only 6mm of air. The only real threat from tritium is ingestion where you don't have air or dead skin layer to block them, but even then they would have to be present in vast, vast quantities to receive appreciable dose from them.