Earlier quoted context omitted.
> It seems more likely to me the manager tried to read it and struggled, then generated something of equivalent size or larger. Either way, it's poor management to interpose oneself between employees. As a manager you should be connecting groups of people to talk to each other directly, not injecting oneself as a go between. If they have issues understanding the material they're much better off asking the OP directly…
The op is probably not the world's most reliable narrator. Based on his very, very specific preferences around writing I'm guessing he can be a bit prickly when it comes to feedback. The manager might have had a bad day and dreaded having the conversation and ended up with this. Still very stupid, but OP is not quite so clearly the martyred hero in this version.
This is the reason professional jargon exists: to narrowly define certain words. But even then, only a tiny fraction of words are so restricted.