Adding: it is disgraceful how sloppy and unscrupulous most opponents of the cosmic impact model have been. They should be ashamed. There is nothing wrong with demanding a high standard of evidence. Failing to maintain even the most basic standards for your own work is, especially in context, inexcusable.
They are righteous defenders of what amounts to the current creation myth of scientism. Nothing to see here when The Science is understood to be a religion.