Strange Comment Behavior. Text Shifting Out of Place in Sentences

One of our faculty experienced the cursor acting strangely when leaving comments on an assignment. While she was typing the comment box would sometimes shirt her text back to a point in the sentence it did not belong. So "The dog ran across the street" becomes "across the street The dog ran".

Has anyone else heard of this? Normally I might think it was user error but this instructor is quite tech savvy.