Sometimes I will notice that the first pet in my party will have no cooldown on mend. However, when the next turn comes around, it 'resets' to the actual cooldown for the skill. It happens periodically and if I click off the sylestia and then let it fall back on him, it will show the actual cool down for the skill once more. However if I use the skill, it uses just fine and sets the cooldown back to normal.

Not sure if that made since or not.