I don't think I would be real quick to throw a shorter shock on there. Is the tire still on the ground when you see the spring off the perch? If it is, at least the unsprung weight on that corner is loading the tire to help make some grip. Going to a shorter shock might just jerk it off the ground sooner.

I would be more inclined to add one of these:

https://www.pegasusautoracing.com/pr...p?Product=1876

I run them on all four corners of my pavement car. It keeps enough tension on the spring that the perches stay seated and nothing falls out. It's one less thing to have to worry about after having the car jacked up in the pits.