Such was the case the other day as I was watching the first Colombo episode: Prescription: Murder.
In one scene, a character (actually, the murderer) picks up the phone, and then hangs it up, and the chord very obviously sweeps around the front of the phone. Actually, the chord almost stands out too much; it's reasonable to assume they put the handset on the "wrong" way so that the actor could easily pick it up - now there's a funny little prop staging detail that probably wasn't even picked up on until they came to shoot the scene.
Anyway, he hangs up (frame 1):
And about five seconds later (during which we're assuming no one made another call) it cuts to another view showing the phone with a very different looking chord. In fact it's so tangled you have to wonder if that scene was shot first, and then they replaced the chord for the first scene. Note to that the handset is turned around...