Jez123 - 12:07 pm on May 14, 2012 (gmt 0)
It seems to me that if the Penguin is triggered it will focus on over optimised links, bought links, content, keyword stuffing, in fact anything and all that it doesn't like. If triggered. If not triggered for one reason or another then it will pass on all of the other things. So once triggered by one issue unless all are cleaned it is not lifted.
That is why I am seeing super spammy links going to sites that have replaced mine in the SERP.
So, if someone does point bad links at a competitor, it may well not do any harm unless there is something else already wrong on site or with other elements of the link profile.