You can also select the type box in Illustrator, flatten transparency, and the extra A disappears. Or if you delete the return so Avoid is on the same line as WARNINGS, the A disappears. The interesting thing is if you smear the entire WARNINGS line with the text tool you can see in the selection what looks like a character beyond the end of the sentence. If you then smear the WARNINGS line and the next line with the text tool that space increases.
My guess is that this is just a corrupt file, which happens sometimes as we all know. One of the checks I used to ask my employees to do when I ran the prepress department was to lay the original type over the outlined version and check closely for any changes. I know this can be a bit time consuming, but one needs to remember that spinning hard drives are really just domains of very small magnetic domains that have either a positive or negative charge and sometimes they get confused.
I hope someone from Adobe would be interested in looking closely at this file. I have seen a lot of type since I started working on the MAC in 1991, including type from early versions of Illustrator, Pagemaker, Freehand, Quark, Framemaker, Corel Draw, and I have never seen something like this.