That's not how it works - causality assessment requires a bit more evidence than an N=1.
There may be some actual affect on auto-immune thrombocytopenia but to say after one case that its "certain" is quackery.
It seems that there have been about 35 cases, and it happens with many different vaccines. The doctor quoted is the world expert on this disease.
This possible side effect is at the bottom of the list of things to concerned about where these ‘vaccines’ are concerned
Causation with such a catastrophic blood disorder may not be as difficult to determine as other maladies. The exact sequence of dominoes that fall to put one in the throes of ITP may not be known but the first domino and the thing that pushed it over? It’s not outrageous for a doctor with his credentials to state with certainty that it was the COVID mRNA jab.