What he is taking about is during the planning phase when you select a card and choose not to cast or to cast it. The card is not in play but it is linked to the spawn point. So if you lose the spawn point you lose the card. Gigan is also correct because the card has not been cast it is not in play. therefore it ca not be attacked or targeted.
Here is part of the spawn point rules
Spawnpoints
Conjurations with the Spawnpoint trait have the
ability to cast spells for you. You select spells for your
Spawnpoints during the Planning Phase, at the same
time that you choose spells for your Mage to prepare
(one additional spell for each Spawnpoint). Usually,
the Spawnpoint can only cast certain types of spells,
as listed on the Spawnpoint’s card. Place the spell
face down near your Spawnpoint, and tell your
opponent that it is the Spawnpoint’s spell. Only your
Spawnpoint may cast that spell during the round.
I have seen player forget to cast a card on a spawn point for 3-4 turns before.