Google doesn't replace them with split versions (except that it ignores punctuation), nor does it replace them with different spellings or related meanings. The words you search for will be there, in order, the only difference will be all whitespace and punctuation is treated as a space.
>string of bytes which I have quoted
That's tricky. What if there's a line break? What if you search for "some text" but the html contains "some <b>text</b>"? Punctuation would be a problem too. What if you searched for something with "-" (hyphen-minus, unicode 0x2d), but the page contained a "‐" (hyphen, unicode 0x2010)? What if you searched for something with a dumb quote, but the page contained a smart quote? What if you searched for something with a space but the page contained a non-breaking space?
>string of bytes which I have quoted
That's tricky. What if there's a line break? What if you search for "some text" but the html contains "some <b>text</b>"? Punctuation would be a problem too. What if you searched for something with "-" (hyphen-minus, unicode 0x2d), but the page contained a "‐" (hyphen, unicode 0x2010)? What if you searched for something with a dumb quote, but the page contained a smart quote? What if you searched for something with a space but the page contained a non-breaking space?