@sunflowerinrain I've noticed this too; I suppose it could be from the pronunciation of the metal. My guess was that it came from analogy with "to read" - the present tense is formed as for the verb "to lead", but of the "read"/"red" homophone pair, you choose the opposite spelling for the past tense from what you'd choose of the "lead"/"led" pair.
@khird
I wasn't clear about the pronunciation, was I? Oops.
I meant that if I don't detect metal in the surrounding text, I automatically hear it as leeeed and am jolted by the present tense.
Read doesn't have the same problem because I hear whichever tense is appropriate for the context.
Spelling...
Ah, good ol' English.