Was Harry Alone?

[fiondavhar]

No: HPFGUIDX 96500

I have come across some evidence that Harry may not have been alone 
when he cast the patronus across the lake in PoA, and I was wondering 
what others thought.

In canon, Harry is (presumably) alone by the lake-side (though it is 
never stated that he was certainly alone, simply no one else is 
mentioned as being percieved), Hermione being in Hagrids hut. There 
has, however, been some evidence to the contrary - one of the things 
that JKR has "hidden" inside the books that she cannot avoid 
displaying, not matter how subtley, in the films ((suggestion - look 
over Harry's shoulder, to the right side of the screen, in the PoA 
trailer - there is distinctly someone there)). 

Does anyone have any theories about who might possibly be standing 
over Harry's shoulder? Could this be related to the speculated time 
travel in book six? Could it be possible that there were not two, but 
three Harry's running around the grounds that night? Or even 
Professor Dumbledore? 

I apoligize because I know this is bordering very dangerously on 
movie contamination, but it is tied in so closley with the canon and 
predicting what will happen therin that I really couldn't help myself!

Bonny, slidling away with her head down hoping she won't be 
reprimanded.