I feel stupid even posting this. Why I never learn with these guys....

Had a neighbor who hired a landscaper (NOT a licensed plumber) to put in an irrigation valve. While chatting with him I mentioned I could use another hose bib on the other side of the house.

As it's a slab foundation he ran copper pipe from front of house, off main entrance line to house, around to side of house. About 50' - I paid the guy $550.00, which I thought high but knew copper is very expensive these days.

Here comes the dumb part. I couldn't figure out why it was so loud and pressure so-so when I used this hose bib. Duh. Finally occurred to me, weeks later, he used 1/2" pipe!! - In my mind it was an obvious rip off to save money on copper pipe. At the end he put a 1/2" to 3/4" conversion so my 3/4" hose could be screwed on, which shows me even more he knew he was scamming me.

My questions:

1) This was done completely wrong, right?

2) Is this a code violation in California?

I know the guy is going to dance when I confront him, so hoping you folks can give me some help. Learned my lesson, finally, on using unlicensed contractors. Thanks in advance. Truly appreciated!