We're reading the same words and sussing different meaning from them.
First I'd ask whether its even possible to suggest a course of action to take when faced with a creeper without that implying that you're blaming the victim.
As far as being professional goes, once again I think David is saying that the best response would have been to stop him cold, because not doing so suggests a passive acceptance of being spoken to in that manner, even if ignored. To do so leaves you in a space where you wish somebody would just take the fucking hint rather than just being clear about it, and stating that you're being disrespected and fucking stop already.
So what I read as professional advice to stop the guy cold in his tracks you read as a statement that she was being unprofessional. To be fair you're reading it in the most literal sense, but I don't think that literal meaning makes the most sense in context.
To be fair I don't see Jaffe as a wordsmith as much as a conversationalist, so when I imagine him saying the words out loud as if we were talking over beers, it makes sense to me. But yeah, thats me reading between the lines and what I know of Mr. Jaffe from his appearances and GAF posts and rants. Which I do when it comes to tweets because you have to.