Would a FOI request to the relevant department not force the issue? It does seem like there is an attempt at deflecting blame/litigation at this point. Experts can be found and data can be analysed via this thing called the internet these days. The crash and physical investigation would have been completed back in 2017. The initial report was written end of 2019. The conflict of interest arose in 2020 but the data is available to be analysed at home/online.