Hang on a mo...
The dyno graph on that company's website is the exact one you linked to earlier. So was that your car they did that to then?
And after a bit more digging, I found that Mazda once created a proper hydrogen RX8, not just an injection device: https://www.carmagazine.co.uk/car-reviews/mazda/mazda-rx-8-hydrogen-re-2007-review/ . If you read that in detail, it explains why a rotary can take hydrogen better than a conventional 4 stroke engine (which is good, and not something I'd thought of), but it also shows that using hydrogen meant that power nearly halves from 192bhp to 107bhp, and a similar drop with torque from 162lb/ft to 103lb/ft. Now obviously there's a difference running an engine entirely on hydrogen to simply injecting a smidge into the combustion chamber, but this isn't helping prove anything here in terms of extra power.
Go to the test results page at http://www.hydrogenhybrids.uk.com/test-results/ and have a read of the 'facts'. You have one letter from a biology teacher with the most god-awful evaluation of his test and evidence that I've ever seen, and even his own results show that immediately prior to the install on two occasions he got better fuel economy than on 6 out of 7 runs after the install. The bike and Focus power tests are a joke, as the bike showed a whopping 1bhp increase (which anyone who's done a dyno will know you can easily get between runs anyway) and the Focus a whole 3bhp more which is a whopping 2% increase on max powerzzz!!!!11
If it looks like a duck and quacks like a duck...
I mean, fair play to you for trying but I'm not convinced this is anything other than all in your mind in terms of any difference at all. Out of curiosity, what did your insurance company say when you told them about the install?