I very often find myself focusing very closely on possible little mistakes that might go unnoticed and sometimes, the bigger mistakes fly over my ahead. Such was the case one פרשת פרה when I missed a biggy. Fortunately, it was in the הפטרה. In (יחזקאל ל"ו:ל), instead of פרי העץ, the בעל קריאה said פרי הארץ!! I heard murmurings and I knew I had missed something but I just wasn't sure what it was so I couldn't very well correct it.
I joked with people afterwards that perhaps it is not such a serious mistake. After all, if you make a בורא פרי האדמה on an apple, you are יוצא, right? It is still אדר.