“3M Execs convinced a Scientist PFOS Found”… ok, the PFOS found the scientist?
“3M Execs convinced a Scientist PFOS found in Human Blood”… PFOS found a scientist in human blood?
The problem is that there are gramatically valid ways to parse partial versions of the sentence, which you have to reparse as you go through the sentence.
https://en.wikipedia.org/wiki/Garden-path_sentence
“3M Execs convinced a Scientist…” ok
“3M Execs convinced a Scientist PFOS Found”… ok, the PFOS found the scientist?
“3M Execs convinced a Scientist PFOS found in Human Blood”… PFOS found a scientist in human blood?
The problem is that there are gramatically valid ways to parse partial versions of the sentence, which you have to reparse as you go through the sentence.