No damage to his ACL doesn't mean "healthy," my friend. People who have written extensively on this the past couple of days talk about how when you get that bone-on-bone collision, which causes a bone bruise, it decimates that tissue that absorbs the impact and protects the ligaments. Your ligaments are good, but there are a lot of muscle and tissue fibers that suffer severe trauma.
Just to bring up an anecdote---not saying the circumstances are entirely the same---Adam Hoge had a very similar injury, a non-contact fibula-on-tibia bone bruise without ligament damage. He's obviously not a pro athlete with pro resources, but he says he basically couldn't move around for three months---The pain was too great and the tissues and fibers too tight from trauma.
We'll ultimately know for sure in the next few days how serious this is, but I would be incredibly surprised if this doesn't sideline Dalton for at least the next several weeks.