Why did squirrelflight dump ashfur?

Ashfur seems to have directed his hate to Squirrelflight. It can be assumed he believes that Squirrelflight, opting to choose Brambleclaw over Ashfur, was the one who was At Fault. Maybe he thought Brambleclaw was an innocent bystander or something. If he did feel any hatred toward him, it's possible he simply chose to hate Squirrelflight instead, because he still loves her. Love hate situation.