Getting cartoon physics wrong

Texting-while-walking dude, not minding his feet, walks partway across pond.

Looks up, finds himself stranded, calls for help 'cause he can't swim.

Come on, that's now how it works.  Everyone knows that when Elmer Fudd walks off a cliff, then notices where he is, there's a brief pause and then he plummets.

When texting dude looks up from his phone, he should have just enough time to recognize his predicament, then sink.