I can guarantee that before the end of this week – and it's almost here – I will, once again, see some variation on this: "He lead her down the garden path to show her the newly planted marigolds."
You're right. It should be, "He led her down . . ."
It seems so easy and yet it's such a commonly made error. Perhaps it's understandable.
"Led" is the past tense of the verb "to lead" – pronounced "leed." "Lead" is a heavy metal, pronounced "led." Confused yet?
Look at the cousin of "to lead" (pronounced leed) – "to read" (pronounced reed). In this case, we're going to say, "She read [pronounced red] him his rights and led [not lead] him off to jail."
It's an odd little mistake because people often know it's a mistake, even as they're writing it. I have very recently seen, in informal writing, "I know I'm going to be lead in the wrong direction – hey, is that right or should it be 'led'?"
Another mistake in the same general ballpark – and of this one, I'm not nearly so forgiving – is: "Don't loose hope. Everything will be fine."
Never mind. If you can keep your head while all about you are loosing theirs . . .
Got it? Lose? Loose? They're not spelled or pronounced alike! No excuse!
Thus endeth the lesson.