why, that man had to be older than he was, and wearing an emerald-green cloak

[diamondcutter]

Mr. Dursley was enraged to see that a couple of them weren't young at all; why, that man had to be older than he was, and wearing an emerald-green cloak!
Source: Harry Potter and the Philosopher's Stone, by J. K. Rowling

I have two questions about the second sentence.

1. Is the word “why” an interjection?
2. Does “and wearing an emerald-green cloak” mean “and he was wearing an emerald-green cloak”?

 

[Peedeebee]

I believe "why" is an interjection, and probably means.. well, almost nothing. You could say, "I say!" or "Well!" or " I ask you!", in an indignant tone, or a surprised tone, or a pleasantly surprised tone. If you were indignant you could say, "Hmmph", which means nothing at all, and simply shows your feelings.
I don't think "why" has anything to do with its normal, literal meaning.
Perhaps someone will correct me and say that in the distant past it was used in a way which was its original meaning.

 

[diamondcutter]

What about my second question? Do you think I'm right?

 

[emsr2d2]

Yes.