I’m explicitly not making any claims about the affect of parenthood on performance in saying that in the absence of any evidence, it is as likely to make you better as it is worse. The burden of proof lies with the GP, who sees it as a risk.
My point is that I didn’t make a claim, I refuted GP’s by saying that either outcome is equally likely as there’s no proven link between parenthood and performance. If GP wants to claim there’s a negative causal link, the burden of proof lies with them.