Yes, they will have to provide some solid evidence that the data is directly Doppler derived. It is possible to 'fake' Doppler. The chip maker would have that documentation.
Error data that is not viewable by the user or in the users analysis software is useless, being completely non transparent, unable to be peer reviewed. Sounds highly suspect to me! If they can see it, then anyone should be able to see it. That is IF they actually have anything!
The 'source code' description is not correct. The chipset itself produces the error and the Sony Chipset does not,can not. Even if it were some sort of 'source code' reverse engineering or something, the Locosys system (not a Sony Chipset) would not work with the Sony Chipset anyhow. It would have to be engineered from scratch for that chipset.
"25Hz ublox based logger"? Hmmm, I dont know that one.

Maybe this is a new Ulbox chipset I have not caught up with? Possible, but why do that when there is very well known M8 10Hz multi GNSS data that is already well known?
I agree Andrew. They will have to do a lot more than throw around fancy rhetoric to get credibility. As has been said before. A few random comparison tests just do not cut it. Proper scientific documentation and explanation would be required at a minimum. Mathematics and a paper might if it is available for peer review.
It will be interesting to see what they come up with to say the least.