And the timing of the individual recall for four boats, which in this case is made after 10 seconds!
As always the question is if a specific time is too long. Like how many seconds you should raise a protest flag or how long after an incident you should do penalty turn(s).
The panel has answered as we can expect: "it depends" and finds subsequently in the described circumstances, that ten second was (too) long. It is long if you count 10 seconds in your head, but it is not long on a heaving deck of a committee boat with force 7 blowing your ears off and you can't hear what the second line sighter is saying. Like the Q&A panel states: 'It depends'.
One of the issues I've learned doing starts, is that your communication with the pin-end boat must be flawless.
Better to repeat your agreed on method for the 50th time, then to have to wait in asking for conformation a second time on how many boats were over. Then those ten second will have passed and then some.
Look at it this way.
If you give an individual recall because you think there was a boat over, but are not sure, subsequently get no conformation from the other people on the pin-end nor the second linesman, you may have hoisted that flag for nothing, but you don't have score anybody OCS.
If you think someone is over and wait for conformation before hoisting the flag, it may be already to late when you get that. And you will be unable to score anybody OCS. Or if you do, that will be overturned in a subsequent redress hearing....
Sure, it is always better to be sure before you hoist the X, so there's no chance that any boat returns unnecessary. But in my opinion to hoist and then find no boat over, is the better of two (not the best) choices.
You can read the Q&A here: ISAF Q&A 2011 - 018 G12