Early on during Kelly's belly dance - after the tempo picks up - the scarf covering her face comes undone, revealing part of her mouth. In the next shot, her mouth is once again covered.
During the opening credits - right after the title appears - audience members watching an ice show at the Los Angeles Memorial Sports Arena, are the same ones as seen in the following week's Pretty Angels All in a Row (1977) beauty pageant (which takes place in fictitious Freebairn, Iowa). Some of the same audience shots were used later for a bodybuilding contest in season five's Mr. Galaxy (1981).
In Part I, when the Angels and Bosley are in Max's office, the viewer sees two differently colored "telephone-speaker" models. The first (beige and silver) is "stock footage" of the one in Bosley's office; the second one (black and silver) is seen in Max's office.
When Kelly is being chased through the arena by Durgus and another thug, she dumps a bucket of soapy water on the floor, causing her pursuers to slip and fall in the puddle. When Durgus enters the locker room moments later, his clothes are completely dry.
As Kelly escapes through the skylight, her shadow is visible against the backdrop that's supposed to be sky.
When Kelly and Kris first appear on the ice - with Max and Alvin talking in the foreground - they spin around and hold one hand straight up. The two women (actually their skating doubles) appear to be approximately the same height but Jaclyn Smith is considerably taller than Cheryl Ladd; a difference their doubles clearly don't share.