I don't know exactly what the issue before the Supreme Court was, but it seems to me that it's not the court's job to determine whether a police chase was dangerous or not. That's a jury's job.
Not that I think the case seems to have a lot of merit to it. Police chase policies can be argued. However, if you're the guy who was speeding and refused to pull over you really don't have a heck of a case if you sue the deputy who took actions to stop you; your injuries are pretty much your own fault. If a 3d party had been hurt in the crash that person would have a heck of a case, but that's not what went on here.
Of course, this is my relatively uninformed opinion. A jury might look at the tape and decide that the deputy's actions were grossly disproportionate for the speeding which was the original basis for the attempted stop. Of course, this article makes it look like the court is not going to allow the jury to do its job (decide the facts) because the court is going to preempt by deciding this fact while claiming to decide a legal issue.