You might have your dealer check for any tsb's on the problem.
or get a All data sub on it.
http://www.alldata.com/products/diy/index.html
Usually feed back on dask lights is caused by bad ground or bulb or socket in tail /turn signal light circuit.
But the blinking is strange deal.
If just one time and everything is still working good.
You may just have to wait and see if it does it again.
If so also wiggle turn signal and light switch and cruise switch and turn off tail lights and see if it changes.
Good Luck
MT