Something I still can't get over....

So you're gonna tell me, no one in Lumon could've told Helena that the gardener lie was bad, and that it was gonna make the innies question things? This lie is the first sign that led Irv to feel that something's off, and made him do all what he's done. Lumon isn't stupid to make such a lie, they would've constructed a well better one. What happened there? Was it bad writing? Just a way to make Irv think about it and give us this big reveal?

Before watching episode 4, I was all team Helly, and my reasoning for that was: Obviously it's Helly, because she was still shocked that she was actually an Eagan, was afraid the other innies would turn on her, made up a lame lie on the spot because not a lot of time passed between the gala and her waking up on the severed floor. She didn't have the chance to make a well-constructed lie, but wanted to hide her identity.

But now that I know it was Helena all along, what's her excuse for the bad lie? Bad writing just to justify Irv's doubting and revealing a big twist? I don't know, but it's still on my mind, and didn't let me enjoy the last episode as much as I should lol.