I was initially with you 100% on this but it turns out that...
"...it is part of World Rugby’s TMO protocols, which were updated and operational from July 1 last year.
"In what is a five-page document, the relevant part reads:
"Should the broadcaster provide an angle after a conversion takes place but before the restart has been taken, that clearly shows an infringement has taken place, then the TMO/referee should use the video referral process to deal with the infringement.
"Previously, it was indeed that if a conversion had been taken, then that was that, no ability for the TMO to come in."
www.stuff.co.nz