There are some cases in which granting the benefit of the doubt is too much of a risk to be worth taking.
With a sufficiently big organization, it's common for some sort of higher precedence, non-negotiable appendix to render most of this stuff moot anyway. Corporate attorneys on the sell-side, even at surprisingly big companies frequently screw this up, often when making snide comments through the salespeople.
My buddy tells a story from when he was an SE many years ago and his company's attorneys were going to kill a deal over an NDA requirement. The customer ended up getting them to agree to "blah blah blah, subject to applicable law". One problem: the customer was a city, subject to freedom of information law in that state!
Experienced salespeople usually get it but eye-roll, as they have an incentive to STFU.
The attorney is the expert. I am not. If the attorney makes a mistake, I have no tools with which to judge whether it was stupidity or malice. I have to assume that it's both. My own attorney may better be able to make that assessment, and I'll respect their judgment. But until then, an opposing attorney has to be assumed to have all of the power and every reason to use it.
I was just saying that I tend to err on the side of stupidity. Most people are stupid. Very few are bad actors in their day-to-day lives.
I'm betting that, if the lawyer was not acting maliciously, s/he used the wrong version of the document to accept changes.