In 2 of the 3 times I've spoken in public for law school, my professors, while ostensibly giving me a compliment, revealed how they had a lowered expectation of me before I spoke. The other time, the professors didn't reveal any judgments of how they thought I'd do when I publicly spoke. But even then while I was receiving feed-back from fellow students, one guy said my personality seemed to switch "on" when I started to speak.
The first public speaking for me in law school was a 10 minute summary judgment (fake) at a local courthouse (real but off-hours). Two days later when our class next met, our professor gave one-on-one evaluations. It's hard to do her inflection justice and subsequently for me to make my point. She said "You really did a good job. I mean it." I smiled, thanked her and went on my way. Later, I thought of how she stressed the word "really" as if she expected me to stand up and speak in hoots and clicks in the courthouse.
The other day, I had feed-back from my professor after my 5min presentation in my tax law course. My professor liked my talk, saying it was fun and how I was funny (No small feat in tax law). She then said how there are some people who are completely different on-stage in comparison to off-stage, me being one of those people. She said she'd like to see me be more like the "on-stage me" while off-stage. Who knows what she thought of me before that talk or what she thought I'd sound like on-stage before I spoke. Like my professor from a year ago, I think she, too, had a lowered expectation of what my public speaking skills would be before I spoke.