when to limp late in tournament?

[technologic]

was watching a friend play a MTT and he was in late stages in the money, around 70 ppl left in a 1200 tournament, and i saw him limp a couple times in MP when blinds were 500/1000 with a limper in front, and he had around 15k in his stack.

i was thinking that limping in these stages is generally not a good idea, and was wondering if there were situations that would justify limping when blinds are this high relative to your stack.

have a specific hand in mind, but will tell of it after i get a feel of what people think.