If it's only a radio-esc interaction issue, there won't be a timing or motor issue. As you are only correcting a reversed polarity issue, you end back up with correct polarity.

Timing-polarity issues only occur if the vehicle requires a reverse rotation motor. Perhaps something like the early X-Factory conversions with the standard 3 gear tranny for example (if I remember correctly they required reversed motors), before they added the 4th gear to get back to standard motor rotation.