[JackFr]

In my experience this effect is real, but I wouldn't always see it in the last line. A coworker proved this to me years ago by making me keep a tally when errors were caused by copy-and-pasted code, versus all other causes. Copy-and-paste won hands down.

[mathattack]

I hear you on copy & paste. I think the last line effect is real, because your attention moves. Interesting article.