OOP: Harry's Mysterious Powers

[Julia]

No: HPFGUIDX 62752

I just want to hear other people's thoughts on this, but in the 
beginning of the book there are two instances that struck as rather 
odd, and maybe I'm just being nitpickey, but they still stand out to 
me.  

First, when Uncle Vernon is strangling Harry, there is some kind of 
unseen "force" that makes him let go, and I don't think it's Harry 
losing control of his magic again, because he didn't seem to be 
aware of Uncle Vernon's reaction, and he usually seems to know when 
he is losing control ever since he joined the wizarding world. 

Second, when Harry had dropped his wand while the dementors were 
attacking he and Dudley, he cried "Lumos," and the wand lit up while 
he wasn't holding it.  And later towards the end of the book someone 
else does this, but nothing happens until they're holding the wand 
(can't remember precise details, but it's when he and Neville and 
the others are fighting off the Death Eaters).

These instances seem curious to me, but I could be the only one.
Any ideas?

Julia Adair