When Teal'c leaves the holding cell, he swipes his access card to open the door. The magnetic stripe is clearly visible and does not pass through the reader.
When the Goa'uld hunter attacks the doctor in the hospital, he manages to remove sensitive monitoring equipment that would cause the staff to be alerted. He also manages to re-connect and replace the monitors on the now perfectly bandaged doctor, despite having no knowledge of Earth-based medical technology.