I'm not sure how they are supposed to prevent this. If you have access to the dns, you can change the record for the origin server that the cdn pulls from. Nothing "horribly wrong" with that.
Akamai makes you to set your own DNS server for it to pull records from, the domain getting hijacked should not have any effect on what that DNS server is returning.
>It added that its domain name system was compromised.
sounds like their DNS server was compromised.
Also, I've never worked with Akamai, but every cdn I have worked with just follows the ns records and resolves against that, which could be changed with access to the domain/registrar. Does Akamai not do that?