When I build a Web page, I rarely start from scratch -- I use a template that I've already tested and debugged, and then change what needs to be changed. The <TITLE> tag is one of the easier ones to miss, because it doesn't appear in the body of the browser window.
For the main design of the site, both campaigns almost certainly used an advertising and consulting firm. Such firms almost always have a partisan or ideological affiliation, so it's unlikely that the same company would have built both Hunter's and Hagel's Web sites. But hosts are usually techies who don't choose clients based on site content, and both sites, according to a traceroute, are hosted by rachkost.com.
But for a relatively simple change that needs to be done fairly quickly -- like putting up a splash page to react to breaking news -- they might have gone straight to the hosting company. If Hagel had a simple splash like that at some point in the past, a coder on a tight deadline would be likely to grab that as a template.
I find sabotage highly unlikely, because if someone managed to get access to the code, why change the title and stop there?
“I find sabotage highly unlikely, because if someone managed to get access to the code, why change the title and stop there?”
The longer you work on a website illegally, the better chance of getting caught.