On this penalty corner, the insertion isn't cleanly trapped and needs to be brought outside the circle by the flicker. He then drags the ball inside the circle and releases it towards the goal, but the ball is blocked by the first runner. The attacker immediately picks it up and drags to the left, and hits a reverse tomahawk into the top corner of the goal.
The central question in this scenario is whether the initial release of the ball that is blocked by the defender constitutes the first shot at goal. The definition provided in the rule book is:
Shot At Goal
The action of an attacker attempting to score by playing the ball towards the goal from within the circle.The ball may miss the goal, but the action is still a โshot at goalโ if the playerโs intention is to score with a shot directed towards the goal
FIH Rules of Hockey, Effective from January 2019, Updated January 2021
As far as definitions go, it's fairly ambiguous. We generally want to avoid the whole concept of “intent”, because it tends to lead umpires to examine the probability of success of the shot. We're not in the business of determining whether a player makes a great decision or not, just that an attempt could score.
When we consider principles, we first need to consider the intent of the rule. Rule 13.3(l) requires the first shot, IF it's a hit, to cross the goal-line at the height of the backboard because the ball is presumed to be traveling so quickly at that point that defenders haven't had enough time to get into safer positions. The next principle is that as umpires, we should only intervene when we're sure a rule has been breached and disadvantage has occurred. In other words, we don't look for reasons to blow our whistle, but reasons to NOT blow our whistle.
In light of those principles, the first release of the ball by the attacker that is blocked by the defender should be considered the first shot at goal. It's directed towards the target, and although it's not a great shot, that's not our criterion. The second shot is a sufficient time after the first to keep the defenders relatively safe. If we're not sure if it's not a shot, we should assume it is and allow this goal to stand.
You can also check out the discussion between Jakub Mejzlik, Keely Dunn and the FHumpires community during his appearance on #UmpireAtHome.