Oh, Wonder, I wish my light had helped more...but I think you did a FANTASTIC JOB! Many, many extra credit points to you, for keeping your cool. It sounds like you stunned H into silence several times. You achieved that objective of showing him you're not destroyed. It almost sounds like you completely flustered him? You also said what was on your mind and your intentions regarding divorce papers, which was good, clear communication. Let him put the "she's not destroyed" thought in his pipe and smoke it for a while.
My friend said yesterday that she thought as long as WAs are in full guilt mode, they attribute any bad feelings they have to their guilt, rather than other emotions that might be more helpful to working out your sitch (regret or desire, let's say, or even anger). When you show them that you're not destroyed, it takes away some of the tremendous guilt and may let them sort things out differently. I think, therefore, that you made the right move. I for one am interested in what his response might be after a little time goes by.
PS The birthday excuse is lame, I think. These WAS's are so weird!