This is all so subjective. Everyone has great points here, though I disagree that it is appropriate to verbally attack or assault anyone. While it's not appropriate, it IS understandable and given the situation that occurs between a WS and BS, a remorseful WS would be willing to give some allowances.
I do agree with bionicgal, and after reading the posts it seems that she might just have struggled to explain why she said what she said.
First, there is no concrete line. Every couple and every situation is different. This argument and the statement in particular are nuanced by the context in which it occurred.
Your WS said you crossed a line. He gets to determine where HIS lines are. That is one for him. You are free to argue the legitimacy of that line based on the pain he caused you.
Your WS tried to ask for some space. I disagree with the notion that WS's should ALWAYS be available to talk about the A. That's a great ideal and if they can it is wonderful for helping the BS heal. However, our WS's are people with their own emotions, frustrations and limits. One might even argue that their brokenness gets in the way of their ability to express and fully feel remorse for their actions a lot of the time, rendering them less capable of shouldering, witnessing and processing our pain. I'm not saying this is right, I'm just recognizing that it tends to exist.
If our aim in communicating with our WS's is to punish them or shame them, then communicating in this way is a good way to do it. If the aim is to gather actual information or find an emotional connection, this form of communication is going to create barriers.
IMHO when we decide to R we make the decision to come together as a team and work toward increasing communication by respecting each others emotional safety and communication styles toward a better connection. To that end, continuing conversations when one person clearly states they are not in a good space for it is disrespectful. And I think you saw how poorly that worked, as it turned into an argument and your need for compassion or validation was not only not met, but negative feelings were exacerbated.
Early in the process we have a great deal of pain. This is a huge trauma. Communication sucks, as we are reeling. It is to be expected that we will lash out, say horrible things, throw the As in the face of the WS every time they express their own feeling or need, etc, etc. At some point, though, a shift needs to occur in which both people see the A as something that happened to "us" and approach it as such.
Did you do anything wrong saying what you said? I don't know. It's not for me to judge. Only you know that. It seems an appropriate thing to say in the interest of sharing your thoughts and feelings openly. The way in which it was said or the timing of it (the delivery) might have been the main problem.
Having read some of your other posts, though, it seems that you are doing much of the work. Your attempts to engage him in the healing process are causing you further pain. If he can't be what you need right now, forcing the issue will only cause more hurt and resentment making R more difficult in the long run. You have some difficult choices to make.
Keep in mind, I struggled with this, too. Every time WS said anything about her feelings or difficulty in our relationship I responded with, "Really? You tell ME about (whatever it was)? Who f%^ked someone with their phone?" I was angry. Yes, she deserved it. Did it help? Not really. I'm not sure responding differently at the time would have helped, either. Distance is what helped. Her having time on her own to figure out what was really important.
Communication is a huge issue for all couples. Figuring out how to communicate better will be important for R. And it sucks to have to do your own work and watch what you say when you are struggling from the trauma of someone else's damaging decisions that wrecked your life as you knew it and in which you had no control.
