Well, it wasn't.
Why would anyone make a near-absolute statement without having experienced the subject matter? If one has not experienced the subject matter, who is he to comment on it? If one does not know, the only reason to be claiming expertise, so far as I can tell, is an unfortunate marriage of stupidity and self-perceived inferiority.
While I don't want to imply that you're lying, I still find that I have a hard time believing that a 9mm FMJ won't penetrate every time at normal pistol ranges.
You have, and may at your leisure, imply that I am lying. As previously stated, whether or not you accept my statement as accurate has not the slightest impact on my day.
Perhaps a HP will expand when hitting the laminated glass and fail to penetrate. I don't know.
I don't know, either. I don't know because I have not fired partially-jacketed ammunition at vehicle windshields. I am therefore unfit to comment on the issue; noting the lack of experience.
I have, however, fired fully-jacketed ammunition at vehicle windshields. Noting the corresponding lack of ignorance with respect to the subject matter, I feel qualified to make the statement; at the height of a typical human shoulder, both while standing and while crouching, the flight path of a standard-load 9x19 FMJ round, from a distance of approximately 50 yards, when fired at the windshield(s) of typical, four-door American sedans from the late 1960's, mid-1970's and early 1980's will result, more often that not, in the subject bullet ricocheting off the windshield without penetrating the glass.
In consideration of this, I re-read the final three words of your post. Those words being the case, I recommend that you consider re-reading the first three sentences of mine.
