Not necessarily. What Tarquin says is that Elan's mother asked him to leave. The court room scene shows us that Tarquin sued for divorce. It's entirely conceivable that Elan's mother just asked Tarquin to leave. Tarquin decided that their split needed to be properly and legally carried out, because, hello, Lawful. This prompted him to sue for divorce, a formality that his Chaotic wife didn't care enough about to initiate.
Edit: In fact, Tarquin states that he's the one that took her to court (although over visitation rights) so it seems entirely plausible that this is what happened.