Two Plot Problems

[justcarol67]

No: HPFGUIDX 187637

Carol earlier:
> > As I've said before, I don't think it was the same spell. The cutting hex that Teen!Severus uses in OoP does no great damage and was certainly not Dark Magic beyond the power of Madam Pomfrey (or even, possibly, James himself) to heal. We don't hear any incantation, either; Severus apparently casts the hex nonverbally, so even if it was Sectumsempra, Remus could not have heard the incantation. But I don't think it was; I think that Sectumsempra, clearly labeled "for enemies," was invented after the SWM as retaliation. But Severus could not have used it at school without being expelled, and Lupin didn't know that Snape was a DE, so it could not have been his trademark spell. 
> 
> Alla:
> 
> But then if it is not the predecessor to Sectusemptra, why use the spell that cuts even if without great damage? I think it was an ancestor to the full blown Sectusemptra, so to speak, the one that was not fully developed yet. <snip>

>
Carol responds:
Sorry to be unclear. I do think that the spell Severus used on James was a precursor to Sectumsempra, a cutting spell of some sort but more of a schoolboy hex than Dark Magic. IOW, it had the "sectum" (cutting) element but not the "always," and any competent witch or wizard could have healed it. (No one makes a big deal about it and James didn't even develop a scar so far as we know.) I just don't see how Lupin could have known about Sectumsempra or called it Snape's signature spell when there's no way that Severus could have used a full-blown Sectumsempra at school and he (Lupin) didn't even know that Snape had become a DE until after GoF. (Presumably, Sirius Black told him about Snape's showing his Dark Mark to Fudge, and Lupin would certainly have known from the Order meetings that Snape was spying on Voldemort for DD. But since Black didn't know that Snape had been a DE, it's unlikely that Lupin would have known either.)

Carol, who thinks that JKR just wasn't paying attention to details here and in many other places