Really? I thought they made it very clear that they were taking a jab at the author, or presumed author, since it's not at all clear that the letter is from a real "high level" RIM employee.

thats exactly what they're doing. they wrote a short and contentless response, and they spent 50% of it pondering if the original letter was real. whether it's real or not isn't as important as the fact it's raising some serious issues.