A Potential Dilemma

Today's error probably won't jump out at you, partly because the sentence in question is rather verbose. Let's break it down. The subject of the sentence is "lack of competitiveness" and "Manning's slow recovery." It's a compound subject, consisting of more than one noun or noun phrase. As such, the plural auxiliary verb haven't must be used with the past participle sunk. The author got this one right. But read on. The problem arises with the words "it has." What does it refer to here? By rereading the sentence, we can determine that it refers to the "lack of competitiveness" and the "slow recovery." Two things. Yet it is a pronoun that roughly translates to "that one." "It has" should have been "they have." The sentence's lack of correctness and Owen's sharp eye have created today's post.