I'm more forgiving of orthography gaffes than I am of errors in syntax. The former may be due to a learning disability, and not reflect on intelligence and education. But grammatical errors? Dat jes be iggorint.
That said, if you know that you have a spelling disability, it behooves you to employ a compensatory mechanism, you know, like a spell checker or a secretary. So, it still reflects poorly on the guy. I assume that he had to earn a degree in order to get his position. One wonders how.
Unless someone pranked him by deliberately sabotaging the letter. In which case, kudos to the kids involved! Good one!