Yeah. For a long time, I thought it was Merry's dagger that killed him (in the books, they say it was enchanted against the Witch-King), but apparently all it did was make him vulnerable, so that Eowyn could finish him off.
Fun fact, the original Swedish translation has Merry kill him, because the translator misread the whole thing. So in Sweden people for decades thought that the prophecy was circumvented because Merry is a Hobbit. Which also made sense, because in the context of Glorfindel's (IIRC) prophecy probably everyone thought he meant the race "Man", rather than the gender.
i was just about to bring this up. i was so confused when the movie had her kill the witch king, instead of Merry doing it ---