During a pitch, If they say:
"Great team!"
"Cool product"
"Great Idea"
"When will that launch"
"Who else is using this"
"When does this go live"
....
you know they think your product sucks..

During a pitch, if they ask:
"Why hasn't anyone done this yet"
"Who else is building this"
"What if GOOG / AAPL / FB did this"
...
you know they are not impressed by your team.

During a pitch, if they ask:
"Who else is investing"
"How much have you raised in this round"
"How is the round going"
"Let me circle with my team"
"How much are you looking to raise"
"Do you have terms set yet"
....
you know they do not have conviction yet

During a pitch, if they ask:
"How big is this market"
"Who is your real customer"
"How big can this get"
"How big is your addressable market"
"How does this get to a 10 billion outcome"
...
you know they don't understand your market