Revealing mistake: "Stop When Red Lights Flash": In the cell with Kate, Weston puts on his mask, making only his head visible. But the blue-screen matte used for this special effect is, weirdly, showing through his blue eyes. (00:23:40)
The Cavern - S1-E10
Revealing mistake: When Jonathan and Nicky are running out of The Cavern during the rockfall a cabinet is knocked over by the vibration, but you can see that it is pushed over by someone with a stick.
Revealing mistake: Many times throughout the series, the wires that hold up and control the models of the Eagles are easily seen.
An Insidious Trap! The Flying Fleet - S1-E3
Revealing mistake: When Hayato attacks Bullface with the Liger missiles, the explosion does not follow at all the outline of the ground, it just cuts away in a straight line superimposed in the wrong spot. (00:18:15)