When the telephone pole was first installed, Mr. Douglas could stand on the roof while talking on the phone, which was placed about a foot from the top. When Eb talks to his girlfriend, he's at the top of the pole with the phone, but it's four feet higher, evidenced by Mr. Douglas standing on the roof in the same position as when it was installed.
When Oliver first picks up the phone, the wires go over the cable. Immediately after the wires are under the cable.
When the porch railing collapses it is obvious to see that Oliver pushed on it when it fell.