there is a ton of ways to use Hawkeye, but this is the one they came up with to limit the delays, but still bring it into use. Most courts don't have it, so remember it is a luxury when you have the opportunity and it makes sure you don't get a major rip at a bad time. also, linesman are part of the game as well. They make far less mistakes than the players do, and maybe less than hawkeye?? probably not, but just cause hawk eye says something, does not make it correct. On the closest ones, I prefer the linesmans call, as it may fall into the margin for error for hawkeye, but the linesman call is the standard.
Mary's problem is her poor explanation of her position, just like on every other subject.