Lead - led
Notice that the past tense and -ed participle forms of the verb 'to lead' are the same: led. Writers can understandably confuse them, particularly when they are in a hurry because, partly, of the English spelling convention that says that the combination '-ea-' can be pronounced in two different ways: like the '-ee-' in 'see' or 'speed', and like the '-e-' in 'get' or 'red'. And lead and led are both forms of the verb 'to lead'.
Led (the past form) is pronounced to rhyme with 'red' and 'bed'. It does NOT sound the same as the present tense lead, which rhymes with 'deed' and 'feed'. There is a confusion about this: see Lead (homograph) for more.
For another possible confusion, see led - LED.