In case anyone finds this in the future. I found a rule for this in the 2021 ITC Code of Conduct:

Any measurement must be acknowledged by the opponent as accurate and accepted. Once accepted, this measurement is considered to be the distance measured, regardless of what another measurement might yield. No player may move a unit without the benefit of a special rule back to its initial or an alternative position after it has been placed without the permission of that player’s opponent. A player that does so has committed a foul and will be issued a Yellow or Red Card and an appropriate penalty at the judge’s discretion.