This totally reminded me of something that happened at work. All the corporate people send emails to the stores, and some of them are posted for employees to read (those include sale changes/ FYIs about store policies, etc).
So one time, our regional director was visiting the store and we were reading one of those emails that had a lot of grammatical errors, including the wrong "their". Daniel (another associate) is a MAJOR grammar person, and said out loud "Man, you would think all these corporate people who climbed up the corporate ladder would know which "their" to use!!!!"
Well, that guy who wrote the email was in the store (regional director

) and he said "Well, it spell-checked ok!!!"
lol it was the funniest thing ever.