I’m sure the AAIB will use their own reliable sources thank you.
I'm not...a non fatal light aircraft accident in the UK will normally be investigated by correspondence. There is a cost-benefit decision about getting other data, which for a Cirrus would include the onboard recorder.
When using FR24's data, like any source of information, you have to understand the limitations of the data you are using. With that in mind FR24 and other citizen reporting type things are really good.