It would be nothing but foolish to replace the good tire. The flat tire was not even damaged, it was reinflated on the rim. You have no idea what the tire is rated for,and you have no idea the load that it was subjected too. It is real easy to spend some one elses money.
Do you think that truckers throw away a set of tires just because one dual went flat? Of course not.
Just keep a close eye on the pressure and temps on that side. If you run another 800 or a 1000 miles with no anomalies I would forget about it.