I believe it's not possible to identify whether tywebb and buchanan are using the same machine. It's possible to show that the two machines are currently having the same IP address at the time of detection but that is not enough to conclude that the two machines are the same machine.
It is not impossible for the two users to have the same IP address as long as they are not recorded at the exact same time.
Furthermore technically it is also not impossible to have the same IP address which is visible to the internet at the exact same time because two machines can share one internet connection via sophisticated wireless intranet.
In addition, it is not absolutely impossible to forge IP address to cause confusion and to give tywebb or buchanan a feeling of satisfaction for successfully tricking boredofstudies.org into believing that they are the same person.
It is also possible that tywebb and buchanan are really good friends and that buchanan gives permission to tywebb to use his webspace.
Besides, it is possible that tywebb visits buchanan often and he sometimes logs in at buchanan's place.
Now, there is not enough evidence to conclude that tywebb and buchanan are the same person.
ok?