Harry Potter discussion

Hello, I'm currently rereading the series and I noticed something in the first book that I haven't paid much attention to back then.

When Harry and Malfoy met the first time at Madam Malkin's, Malfoy mentioned to Harry that his mother had gone to buy his wand for himself.
How was it possible when Ollivander later said to Harry that "The wand chooses the wizard" and not the other way around? It seems that not "choosing" the wand for himself wasn't really a problem for Malfoy later on. (At least as I remember that right now.)

What do you think about this issue? Is there an already existing theory about that?

“My father’s next door buying my books and mother’s up the street looking at wands,” said the boy.

I don't think Malfoy meant that his mother was actually buying the wand for him but might've just have been waiting for him up the street, looking around the wand shop or something. But I agree that it's weirdly phrased.

Luna wrote: " “My father’s next door buying my books and mother’s up the street looking at wands,” said the boy.

I don't think Malfoy meant that his mother was actually buying the wand for him but might've ju..."

Okay, thank you.