A completely Luddite misunderstanding of modern Canbus systems.
CAN transceivers are short circuit protected by design. An accidental short will result in no damage or "expensive" repairs. At most a simple clearing of fault codes once the short is removed is required.
From Google:
"Signals are extremely low current signals and, by design, no damage will occur if either CAN High or Low are shorted to each other, B+ or ground. I have seen many shorted CAN signals caused from rodent damaged wires or faulty control modules and no damage was created by the short. Note that power-train CAN buses can not operate on "single wire mode". If either CAN high or low is shorted the communication will stop on the entire bus. Usually body related CAN buses can operate in single wire mode. If you do accidentally short either CAN signal you are likely to induce fault entries into the vehicle control modules that will need to be cleared after the wiring is repaired."
Tom