Paul Martin is not a valid authority on this. He is a known anti-hydrogen skeptic and had made many nonsensical claims about hydrogen. The most notable is perhaps his limited understanding of how fuel cells work, and his claim that fuel cells can never dramatically exceed the efficiency of diesel engines.

This is false, as fuel cells are electrochemical systems that do not follow Carnot's theorem. Which is to say that it is fully possible to build a fuel cell that greatly exceeds the efficiency of diesel engines.

Not to mention that most of his claims are from some years ago, and are becoming obsolete even if they were true. He has not commented on (AFAIK) about the effects of subsidies nor admitted that costs are dropping rapidly. He just sounds like another anti-renewable skeptic similar to those that criticized wind and solar.

It's worth mentioning that all of them are similar in a way: Old, retired or nearly retired, and usually coming from in the fossil fuel industry. And yes, Martin is from the fossil fuel industry, and has no experience with hydrogen beyond its existence as a feedstock for oil refining. He has never had any experience with modern hydrogen-related facilities, equipment and concepts.

Engineers that actually do have experiences with those area do not agree with Paul Martin. So there are alternative viewpoints from knowledgeable people. You can look at recent statements by BMW and Bosch, including what their engineers have said. They are clearly believers of the idea:

https://www.repairerdrivennews.com/2022/09/01/bmw-bosch-anno...