The fluid could be soaking into the subframe mount and may have loosened up the mount a bit. I could maybe see that if the bolt is loose combined with fluid that got between all the mount points. May cause it to shift a little more than it should.

I know they can take a lot of abuse but at a certain age all things rubber degrade, hence why I'm changing mine. After 24yrs., years of on and off leaks and 500K+ miles on them I'm sure they could use a refresh.