How long ago?

Any writer who's known me for long knows I abhor the word "got." (To recap: Frequent use of "got" is the sign of a sloppy writer. In almost every instance "got" can be replaced by a better, more accurate, more descriptive word or phrase.)

Lately, there's another word that's been bothering me almost as much: ago.

Unfortunately, many writers, editors, and readers don't understand its proper use in a time sequence and bollix up their stories unnecessarily.

For example:

At the end of a long, hot summer, Little Tony finally had had enough. He pulled a snub-nose .38 from the holster attached to his belt at the small of his back and drilled a pair into the little prick who'd been riding him the entire time. He had never intended to harm his wife's younger brother, but three days ago the simpering fop had pushed his last button and Little Tony only had to wait until the two of them were alone to scrape that pimple off the world's ass.

Whoa! Wait a minute! When did the simpering little fop push Little Tony's last button?

Grammatically, the simpering fop pushed Little Tony's last button three days before this story was told, which might be--because this is written in past tense--days, weeks, months, or years after the shooting.

What the author meant is that the simpering fop pushed Little Tony's last button three days prior to the shooting.

Therefore, the author should have written:

He had never intended to harm his wife's younger brother, but three days earlier the simpering fop had pushed his last button and Little Tony only had to wait until the two of them were alone to scrape that pimple off the world's ass.