I didn't attend the elevator pitch webinar but did attend the one on "Slush Pile Live" and I agree with Iren's comments. I was very surprised by what the agent didn't say about the first two extracts in particular. I'm sure most of us in J.W. aren't so sensitive that we can't take some criticism of a constructive kind, disappointing though it might be sometimes. We tune in for help to be better writers.
To be fair, there's a time factor involved in the webinars and this means that whether or not your question or entry is picked for attention is very much a matter of chance. As Enmaloo has suggested, there is a case for these things to be stated beforehand in time for scrutiny by the speaker. Perhaps this would give more people a chance to be heard and responded to in a more considered way, so that they would be speaking less on the hoof.