Thank goodness it wasn't disallowed on a technicality. I know it's a bit more subjective and that there have been instances where tries that anyone who has played Rugby League knows are fair, have been disallowed, creating an unfortunate precedent…but Mannering had no effect on the play. Should be a try any day of the week, and made an otherwise terrible game memorable for dramatic theatre.
The tendency to disallow tries dogmatically on technicalities also leads to defenders who have no chance of making tackles finding the nearest opposing player to collapse into in hope of attracting a no-try ruling. Not a good look for the game.