When a suspicious Tina is checking up on Kris' real estate license, there's a large blue file on the desk that Glenn puts a manila folder on top of. The camera angle changes and although his hand is in the same place, the folder is gone.
At about 44:50, a character uses a wall intercom, his right arm hanging by his side. But when the shot changes, suddenly his right hand is on his hip.
Both Tyrone and his secretary are supposed to be French, yet the actors never learned the proper pronunciation: even if one concedes suspension of disbelief for the accent---since the actors are both Americans---in French, you do not pronounce ending consonants. Yet Tyrone is saying words like "ha-ree-KOTE VAYRTT" instead of "AH-ree-koh" (haricots = beans) and "vayrr" for "verts" (green). The same for "croissants": the ending T is silent.
When Dick Gautier as Barry introduces Tiffany "Ludlow" to Jake Pickens (Bosley) he says Tiffany's name correctly throughout the scene, except the final time he says, "My philosophy exactly, Miss Laszlo."
The actor playing Tyrone often switches between pronouncing the R properly in French (a guttural sound) to rolling his R like the Italian he is. Also, he pronounces the ending consonant "D" of "épinards" (spinach): instead of correctly ending with the sound "R" (NAR at the end), he adds a "D" to the end, as in the word "deux". (That is always inaccurate.)
Tyrone is supposed to be French, but the actor's mannerisms are Italian. (Ex: being very animated and speaking with his hands, in typical Italian gestures.) Vito Scotti, who played Tyrone, was indeed Italian-American.