What do you do?
Judges, feel free to discuss this scenario on Judge apps!
[expand title=Answer]Alright, solution time! As was correctly identified by many of you, casting an instant does not cause a trigger to be missed because the instant could have conceivably been cast with the trigger on the stack. As such, there is no infraction in this scenario, and no fix is necessary. Give a time extension if your ruling took more than a minute and let the players get back to playing Magic.
Some judges may be inclined to rule this as Drawing Extra Cards because the player didn’t give their opponent an opportunity to act after the last breath but before the trigger resolved. While we would certainly prefer to have the player communicate better, there’s no harm done unless their opponent had a response for that time. If the opponent wanted to do something, that would make this a GRV before the card was drawn, and as a result we would issue that GRV to Ajani and rewind the card draw.
As always, thanks for your participation in the Knowledge Pool, and be sure to check back on Wednesday for our newest scenario.[/expand]