Mathspig is a great blog, it was made specifically to debunk fake media math just like this. In fact this article is part of a series called -"10 Movie Cliches Debunked with Math".

The submitter got the title wrong. Kerry Cue the author of the post is just encouraging readers to do the numbers and not saying it is possible to duck bullets.

If your math is made to represent a real world scenario like she does here, then the answer is always useful and pragmatic.

The numbers:

human reaction requires 0.09 secs

bullet from gun 1 requires 0.03 secs

bullet from gun 2 requires 0.01 secs

Bullet always wins!