Yes, AFAIK. Did they actually recover hit points? The heal spell effect would still play if Loic healed another NPC.
Do you happen to still have saves during or before these fights, where this is reproducible? The unholy alter may be an exception, but skills and scrolls should cause damage if the character is still under the effect of Decaying Touch. Maybe there is an issue with the skill, or status icon was still shown after the effect wore off, or something.
