I cant get any of these to show Spell Lock or Devour Magic.
Somebody on IRC suggested this could be a core library matter post 2.0, and that parser or such would need checking. I dont know the proper way to post this as a "bug" or if this is even what's going wrong, but hopefully this is flagging a problem somebody can fix.
Parser lets you show spell casts so it makes sense that it would let you show spell fails but if SpellEventsLibs comments are correct then its not possible to show anything but the players interrupt/fail. SpellEventsLib has comments saying only the players events are shown via UNIT_SPELL* when it comes to interrupts/fails. :\
Devour Magic would probably show up as a dispel and spell lock would show as a debuff. You can probably add a trigger to Parrot to show spell lock on your target but I dont think it lets you show the dispel I dont use SCT/EavesDrop so dont know if they can show them.