Harry's Scar

[severusbook4]

No: HPFGUIDX 77330

Okay, I admit that his scar does resemble the ruin Ewaiz (sp?), but 
everyone in the book says the scar was created by LV's spell that 
was meant to kill Harry.  DD says it, Hagrid says it, and so forth.  
I know no one was there to see the scar created as the green beam of 
light bounced off Harry's head and back to LV, but JKR is not vague 
in the recounting the events of the night.  She leaves out only 
descriptive details.  If the argument of Harry didn't come back out 
of the wand in OotP, well, the spell didn't work, so, IMHO Harry 
would not be in there.  What I am asking is, where did the the 
belief come from that his scar is not from LV, but from his mother?  
Is there something in the book?  Or is this purely speculation that 
has a small cult following?

Severus "just the facts, maam" Snape