Now, say there was like 3 seconds left on the clock, and our human player tosses a ringer and the clock expires and then the ringer lands perfectly on the rack. is it like basketball where if its in the air like that it still scores, or because it landed after the the clock expired does it not count?
same goes for spoilers
I’ll admit I haven’t read the rule book. But in years past, the playing feild is final when all objects have stopped moving. So in your case, it would count.
It would also help to ask these questions to the GDC since they are the ones that tell us what is and is not going to happen. We are all only players of the game and can only give you what we think.
But i have to agree that it is not done until all game pieces and robots have stopped moving.
This has been brought up in the Q&A for robot bonus points in the end zone. Here
Unsure on the ruling for fly tubes at the buzzer. Could make the game very interesting if Human Players start making tubes in the final seconds
Q&A disagrees. See here. Refs won’t wait for everything to stop moving before scoring. Of course there’s some delay before they get on the field, etc. So chances are the ringer scores. But no guarantees this year.
Scoring may not count.
Last year they would not allow any rolling poof balls to score after the buzzer sounded.
Just my $.02 
Personally, I don’t think this would happen ever; the chances of it are slim to none, based on the playing field. (PM me if it ever does, I would love to hear about it)
Also, unless you threw it up really really high, the time it takes for an object to rise and fall n feet/meters is pretty fast (based on physics :p), meaning that with 3 seconds to go, it would probably be scored. And if you score like that in the last 3 seconds, it would be near impossible for the other alliance to react.