[Jim S]

OK, you're not going to be able to give back the "advantage" that B gained by being ready for the next play.
What you can do is give back the time on the clock. Put the seconds lost (and maybe 1 more) back, make sure the offensive captain knows that you're going to start the clock on the whistle ("and be sure to be on the line and ready"). Then hold the RFP until they get there and are set. At least to the point where they were beore the whistle.
Now you have deleted the situation. No one has to have a flag, or have yardage marked off.

The action that caused the problem was not B calling for a T.O., it was the L.J.'s mistake by granting it. B should not be flagged for that mistake. The R knows the principle, otherwise he would have flagged B when they first called for the T.O. If the act was a foul it has to be called whether or not an official makes a mistake and blows the whistle.

Note: An inadvertant whistle shouldn't even be mentioned here. An IW only occurs during a down. Not before or after.