Sentence:  Not really, but perhaps I'd have got an ‘<WSD>E</WSD>' in Tech Drawing no matter how much I'd asserted myself. Maybe Mr. Pinkerton would have seen to it that my exam paper was tampered with. A spot of teacher to student revenge. 
Meaning of the word marked with <WSD> tags:  The grade below D in some grading systems. In most such systems, it is a failing grade.