Yes you can count the number of letters in the grid, but it's normal in most puzzles in other newspapers to have the solution lengths after the clue.

This is important with multi-word answers because 14 spaces could be a 14-letter word, or a single letter followed by 13, or 2 letters followed by 12 and so on. In cryptics (which this isn't, really), knowing the letter distribution in multi word answers is essential to it being a pleasant and fun puzzle in my experience.

That would have prevented this trick working, because you would have to give the length as (7, 7) for "CLINTON ELECTED" or (3, 4, 7) for "BOB DOLE ELECTED" depending on the "right" answer.

Omitting the lengths allowed this little game to work. It would not have, otherwise.

A bit further in the article :

> Of course, the same device couldn't have been used in a standard cryptic crossword as word length breakup of solutions - (7, 7) vs (3, 4, 7) - would have given the game away.

Clinton would be 7 letters, Bob Dole is two words, 3 and 4 letters respectively.

I've never seen a crossword that does this, the ones I see just use the grid to show word breaks. However, I've also never seen a crossword that has one hint that cuts across a black square, like this one does. But I'm not an avid crossword puzzler.

Cryptic crosswords usually provide the lengths of each word in the solution as part of the clue. If that were done here it would have spoiled the ambiguity because either answer would have had (3,4,7) or (7,7) in the clue.

I think this site probably deals more with the cryptic crosswords, so that aside probably made more sense for regular readers.