It depends on what you compare it to. A DRG jumping in FFXI means you have to wait a second more and cast cure again. A DRG jumping in FF5 means an attack round passes and you missed your chance at healing the DRG and he will jump again next attack round too and you'll never get to heal him.

In that sense it is no problem at all in FF11. But of course one would love to be able to heal DRGs at any time.