In captivity, Marshall's computer changes between PC and Mac.
In the end of the episode Marshall receives a warm welcome back to SD-6, including from Dixon, seeming like he sees Marshall for the first time after his abduction. However, Dixon was with Sydney on the rescue mission in Mexico, so it is unlikely they haven't spoken since his abduction.
When Sydney is rescuing Marshall she is wearing a red hat which falls off as she is fighting a guard but in the next shot she is wearing the hat again.
The tall building shown after the Ho Chi Mihn introduction, pictured next to a pagoda and warehouses with Chinese writing, is really the Comcast/NBC/Universal Tower at Lankershim and the 101 Freeway at Universal City, Los Angeles, California, USA.
When Sydney and Dixon are rescuing Marshall, Sydney plugs into the surveillance feed, Dixon links up via his laptop and a sign flashes on Dixon's computer that says "remote modem signal recieved". Received is misspelled.