Dang, that is funny. If someone uses a word that I don't understand, then that is a compliment on them! And, I will either make a note to look it up later, or ask them on the spot to help me understand the meaning. Granted, rule #1 for public speaking is, Know Your Audience, so you should already know which vocabulary is appropriate.
There is nothing better than insulting someone with words that they do not understand! That's a double insult......go educate yourself so that you can understand the insult you just received, lol.
Yeah, I used to compete in speaking events in high school. Using fillers often is guaranteed to keep you out of the running for winning any speaking event.