Yeah this is a good call-out. If the site is being used for drive-by or targeted malware there are other checks that may be happening alongside the redirect such as user agent, country of origin (like you mentioned), plugins installed, OS, or even time of day.
If they detect something that matches what they want, they may throw some intermediate 301's to pages that attempt to infect the user with something still ultimately redirecting to the "normal" page.
