When the attempt is made on Kallas's life in the prison you can see that he is still wearing his rings. For security purposes, no prison would allow a convict to wear jewelry.
Amanda was captured by Kalas and brought to his lair, after she escaped and found Duncan, she should have been able to tell him or Joe where Kalas was so that they could get the disc from him.
At 33min00 mark (DVD), when Joe Dawson's file on the CD-ROM is displayed, it is stated that one of his previous assignments as a watcher ran from *1071* to 1974. It is obviously mistaken with 1971, since Joe isn't an immortal, and since 1971 would match with the dates of the item below : "Historian (1968-1970)".