Well - remember in the first few episodes of TNG S1 Data used contractions just fine. Then, suddenly as of TNG S1 - "Datalore", it was said Data COULDN'T use contractions.
[Guess Data's operating system was based on MS Windows; and he must have gotten an update depricating his contraction speaking abilities...]![]()
Worse is that the mistake happens in THIS episode still, when it eventually becomes a plot point too.
As a director or script supervisor, I feel like I would've gone through Data's dialogue with a fine-tooth comb to avoid this mistake, or correct Spiner if he happened to slip up a take.