Also telltale sign someone's not plugged into SV - looking at salaries rather than total comp. Then there are two further schools of thought: granted vs. vested compensation. What was your offer + refreshers at grant value + expected bonus vs. what are your initial grants and refreshers actually vesting at + what is your real bonus.
On one hand, you could say that vested comp mostly reflects the outcome of the equity lottery and doesn't have anything to do with what is actually the going "market rate". On the other hand, vested comp is what the person is actually earning. And because of that, it's also their opportunity cost if they were to switch to another job, which in a way does become the market price for that person (at that point in time). Although once appreciated grants fully vest you can hit quite a cliff.