When Peri falls off screen, the mattress she lands on causes her to bounce back into the shot briefly.
In the early exterior shots of Androzani Minor, matte effects are used to enhance the location with painted mountainous terrain. The camera that is filming the live action location is noticeably unsteady, while the matte terrain remains completely still, making the division between the sections obvious.
Peri pushes herself off the ledge in order to "fall".
The handheld device Morgus uses in his office is a Grundig television remote control (model number TP400TT) from the early 1980s. The props department made no attempt to dress the unit in any way, and although actor John Normington keeps his left thumb over the Grundig logo, the model number is still visible.
When the TARDIS lands on Androzani Minor, mountains can be seen in the background (superimposed). When the camera angle changes (though not very greatly) they vanish from the horizon, and reappear again when it switches back to the original angle.
All-American girl Peri makes a remark about forging sand into glass, pronouncing it "glawss" in a very British manner.