Hrewsahgs: How about adding a stone for each side to make the E1 atari legitimately sente? For the defender, somewhere around J3, and for the attacker, G5 to somewhat limit the effectiveness of the H2 clamp or the G3 cut.
Sadaharu: Feels a bit weird to assume P1 atari as sente in the correct answer's variation.
posetcay: I agree, but I don't know how to fix the issue. If we add stones outside, black can simply connect in sente after F18 to live, making the tsumego trivial.
How about adding a stone for each side to make the E1 atari legitimately sente? For the defender, somewhere around J3, and for the attacker, G5 to somewhat limit the effectiveness of the H2 clamp or the G3 cut.