Journalists being shown demos in controlled circumstances are a notoriously unreliable source of information about the viability of a product.
However, I think that in this case, the author of the tweet has a lot of credibility (https://twitter.com/AlexRoy144/status/791996855114694657) as the holder of multiple performance driving records. You're right that it is only one anecdotal perspective, but it's kind of like a prominent Apple blogger tweeting that a new Microsoft product has phenomenal UI. It's just one perspective, but (to me) it's interesting enough to merit further consideration.
To stretch your analogy: when the FCC sends Microsoft questions about the product's RF emissions, does the prominent blogger's endorsement really matter? Firstly, RF is out of the blogger's wheelhouse and secondly, hypothetical Microsoft ought to have planned for regulatory compliance from the beginning, or at least have the technical specs recorded somewhere.
Journalists can be manipulated, but Alex Roy's tweet (https://twitter.com/AlexRoy144/status/791996855114694657) is more an endorsement by a car enthusiast with 30+ years of high performance driving experience than a journalist, IMO.