re: assertions without evidence
As someone who claims to be knowlegible in risk assessment you should know a known hazard is always considered a higher risk than a speculative hazard for which there is no supporting evidence.
The relevance of Hoyle's poorly supported flu claim is Barry's low standard of evidence in using it to support his claims of xenobiological risk while ignoring or discounting far more supported evidence of the possibility meteorite mediated transfer of life from Mars if it existed.
Regards,
Mark