I agree Starsky, but as we see here many times, one thing its to set a boundarie and another different one its to send that email....
I encourage people to have boundaries, but I strongly believe that boundaries our for ourselves , and we have to learn how to communicate them...
For me, he was very upset and just exploded all his frustrations on that email, I think if he approached that in a different way it will have a different outcome... For example instead of that email he could had said something like, I would appreciate if you had communicated me this decision earlier, I would have conduct the situation in a different way and wouldn't have to face some ot the problems this has caused me.
That for me will leave room for her not to get defensive and to really think about what she did and if she doesnt want to think about it, I dont think that his email would it make her think about it....sometimes its better to approach a person leaving room to reconsider if they are doing a mistake than to demostrate them that they are doing a mistake....not many people reacts possitively when somebody probe us "wrong"
Thats my humble opinion
When the student its ready, the teacher will appear... Even after all this time the sun never says to the Earth, "You owe me." Look what happens with a love like that,It lights the whole sky.