[Columbine]

As misguided or tasteless and fumbling as it might be, it seems almost like that's a strange attempt at a light, chummy joke. A blokey "man, this is awkward, let's make a joke about it or else this is too heavy" kind of sentiment.

It might be overly optimistic; I don't know as I don't know your situation very well, but I would take the message inside the card with more weight than the printing. After all, one he bought, but the other he wrote himself.