If I remember correctly what the 6th maiden said, Agahnim "cracked" the seal with the power of the six Maidens and then trapped them in those crystals. Only the power of the seventh maiden, Zelda, could break the seal completely.
But this "crack" might have been big enough for Link to slip in and out of the Dark World...
Yeah that seems more realistic than Link simply bypassing the seal altogether.
Isn't there also a debate about whether Agahnim was actually Ganon or simply someone who Ganon had taken control of? I mean even if he was a normal guy at first, for Ganon to use his influence on Agahnim, the seal would already be cracked in the first place for Ganon's power to enter the Light world. As we see in The ALTTP intro, he had sent all the maidens into the dark world and had Zelda imprisoned in the dungeon, but I'm even if he was Ganon or simply Ganon's puppet, to be under the influence of Ganon's powers I think the seal would have needed to be cracked before Agahnim sent all the maidens into the dark world.
I remember posting like a year ago in the mailbag and whoever responded said that gamers were never actually told who Agahnim was. The guy who wrote this had a theory that the first time you fight Agahnim, you kill a man who is under Ganon's influence, but the second time it's actually Ganon hiding i.e. You kill him he turns into a bat and hides in the pyramid of power.
Anyone have any thoughts about this crack in the seal?