Proofreading

I always found the most difficult part of the writing process to be going back to proofread a paper once it was done. Admittedly, I rarely did it while I was in school. Now that I'm a big boy in the working world, I'm much more cautious before I submit something for someone else to read. I'll read an e-mail two or three times to make sure it is grammatically correct and conveys the ideas I intend before I click send.
Not everyone checks what they do as cautiously as I do. I'm getting a new boss at BuCorps next week. The things I know about him I can count on one hand, but I've already got a bad taste in my mouth. My front line supervisor sent him an e-mail welcoming him to the job. He replied that he was excited for the position and yadda yadda. His response also included a grammatical error. I don't purport myself as having excellent grammar, I'm a computer scientist. It's not what I do. So, when I notice a grammatical problem, it's there. For me, the problem is bigger than a grammatical error. This guy either didn't proofread the e-mail he wrote or proofread it and didn't recognize the error (his subject/verb agreement was off). Either way, I'm nervous:
1) It was a simple e-mail; a middle school student could have written it. If he didn't recognize the problem, there are several universities which need their degrees back.
2) If he didn't proof read it, I'm going to be working for a man who doesn't care enough about the first impression his employees will have about him to proofread a 3 sentence e-mail.
Yes, it's shallow for me to think like this. But, is it to much to ask of someone making over $120,000 to proofread something? I hope not.