When a new smell emerges immediately after electrical work, and the smell has any chance of being electrical related, that is an emergency.
Fire inside the walls of a building is the most insidious type of fire, because it can smolder for hours and become fully engaged before it is obvious the building is on fire. A homeowner can't really fight a fire inside a wall (and sprinklers won't work on it)... but worse, it can spread to the whole house rather quickly, and that can catch you off guard.
It's possible they damaged a cable, or more likely, pulled a wire out of its terminations. If your range wiring is 3-wire and they damaged neutral, that creates an electrocution risk to boot!
But most likely we are dealing with series arcing from a damaged wire or connection. Find it, and kill it with fire (figuratively)... Before it kills you with fire (literally)...