Snape's memory

[Wade Caroline]

No: HPFGUIDX 151851

I have a question:
   
  In OOP when HP retrieves Snape's memory of being tormented by James Potter,  I wondered at the time if Snape's memory of that torment  and what ACTUALLY happened would be the same. I thought JKR  would be reveal later  that Snape's memory was not exactly what happened, thus keeping James' image intact.  Even after Sirius and Lupin admited that they were, in fact, jerks, (only teenagers after all) I remained unconvinced, because it seems to me that one's memory of what happened when one is being bullied would become embellished over the years. 
   
  Am i wrong? 
   
  wc