I think tptacek thinks in a way where he's giving you charity in an uneven discussion, so he's not obligated to go further; perhaps harsh, but his reputation warrants a little pause before simply saying "bullshit".

His reputation is specifically why I asked for a source. While I don't doubt he's an intelligent individual, I've noticed that he also likes to "shoot from the hip" without providing evidence of many claims he makes on both here and Twitter.

No, his reputation doesn't "warrant" anything. Internet discussions don't work this way.

If he claims something, he should be able to back it up with something else than his so-called "authority".