Something caught my attention as i was watching the video of Singapore qualifiers.
Not sure how much life the opponent (with snowman) has, but if as long as he has more than 2300LP to survive the attack from gear x, then he might be able to survive that turn. regardless, i am trying to highlight the importance of knowing the various substeps of the damage step.
Lets have a look at these 2 cards: Drilloid and snowman.
Effect: If this card attacks a Defense Position monster, destroy the monster immediately with this card's effect without applying damage calculation.
Effect:When this card is flipped face-up, select 1 face-up monster on the field and destroy it.
So, lets have a visit to the various sub-steps of the damage step: taken from pojo, and i have taken only the key points of various substeps.
The damage step:
Substep 1. Start of the Damage Step
Some cards have effects that activate at the start of the Damage Step. Monsters like "Steamroid", "Rampaging Rhynos", "Crystal Beast Topaz Tiger", "Etoile Cyber", "Super Robolady", "Super Roboyarou", "Black Veloci", and "Jain, Lightsworn Paladin" with Continuous Effects that are applied when attacking a monster, attacking directly, or being attacked are applied at this time without starting a Chain.
Some monsters have Trigger Effects that activate when attacking a face-down monster and start a Chain at this time because they do not flip the face-down monster face-up, like "Neo-Spacian Grand Mole", the "Mystic Swordsman" cards, "The Six Samurai Irou", "Razor Lizard", "Sasuke Samurai", and "Sasuke Samurai #4". Each of these effects destroys, etc. the monster without flipping it face-up or applying damage calculation.
Substep 2 Flipping the Face-Down Monster Face-Up
If the monster being attacked is face-down, it is flipped face-up at this time. If the monster has a Flip Effect or a Trigger Effect that activates when it is flipped face-up, the effect will not activate at this time.
Sometimes the flipped monster will have a Continuous Effect that causes it to "self-destruct" if proper field conditions are not met ("Giant Kozaky", "Zombie Mammoth", "Thunder Nyan Nyan", etc.) When this occurs, the monster is not immediately destroyed. Damage calculation is still conducted. If the monster is destroyed by the battle, its effect is not applied. If the monster survives the battle, it is destroyed by its effect after damage calculation.
Substep 3 Before Damage Calculation
The effects of cards like "Drillroid" and "Ehren, Lightsworn Monk" activate at this time, after the face-down monster has been flipped face-up and before damage has been calculated. Sometimes these effects will state something similar to "without applying damage calculation", which means that damage calculation will not occur and will actually be skipped over. (The remainder of the Damage Step that occurs AFTER damage calculation will continue as normal)
Substep 4 Damage Calculation
Substep 5 Battle Damage - After Damage Calculation
Substep 6 Resolve effects.
After damage calculation, the infliction of Battle Damage, and any effects that activate as a result, the Damage Step has a section devoted to dealing with the Flip Effect of the Flip Effect Monster that was flipped face-up by the attack. If the flipped monster had a Trigger Effect that activates when the monster is flipped face-up ("Royal Keeper", "Nightmare Penguin", etc.), it will be activated at this time.
Substep 7 End of the Damage Step - Monster(s) Destroyed by Battle are Sent to the Graveyard
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As you can see, snowman eater effect activates at substep 2 and flips face up while drillroid was mentioned specifically in the example that it activates in substep 3. that is to say, when drillroid attacks a face down snowman, snowman's effect can be activated since it takes place at substep 2.
Wikia also has this scenario updated under the rulings section, Jap wikia also has this too.
Q:このカードで裏側守備表示のリバース効果モンスターを攻撃した場合、リバース効果モンスターのリバース効果の発動タイミングはいつになりますか。
A:《ドリルロイド》の効果処理後になります。(05/05/26)
Q: If you attack a monster reverse effect of the backside defensive display with this card, the timing of the imposition of a reverse effect or Effect Monster When will reverse.
A: Will be processed after the effect of "drill Lloyd": A. (05/05/26)
Q:このカードで裏側守備表示のモンスターをリバースした時に効果を発動する誘発効果モンスターを攻撃した場合、誘発効果を発動しますか。
A:はい。発動します。(05/05/26)
Q: If you attack a monster to trigger the effect of inducing effects when you reverse the monsters of view behind the defense on this card, do you want to invoke the induced effect.
A: Yes. And will be fired. (05/05/26)
yup, so thats about it. haha