He’s referring to the crash that killed “Juice” and 2 other pilots, plus the 6 who were killed when the 2 Mi-8s collided fleeing an SU-30. That’s 9, so not unreasonable to imagine 1-3 more died somewhere along the front or just some Russian misinformation the poster read.
OK, I see how the reference was to recent Ukrainian training accidents.
Perhaps NATO is allowing Ukrainian pilots in training to fly into Ukraine for purely defensive missions, to shoot down cruise missiles. Interdiction rates seem high recently.