Corrected Permission Slip

In Elementary school I came home with a permission slip that needed to be signed.  When dad read it prior to signing he felt like the grammar was not correct.  Using his ink pen (that he always kept in his pocket - he also had pencils with little metal clips on them to keep them in place) he corrected the paper.  I was so embarrassed to turn in this into to my teacher.  At the time he realized that what he had done could be taken badly but there was nothing to be done about it.  He had written in ink and I had to turn the paper in.