IMO, Tago's try looked more right than wrong if they were going by the letter of the law. His arm was carrying it in a way were they couldn't prove he lost it, and at the same time his body fell on it and giving that false impression he had lost control.
When we score tries, we have to score them in a way that we force that ball down, instead of going through the motions of thinking we have scored before we have grounded the ball.
This is another issue they have to improve on. Notice when the Storm used to score over the line, and they were so definite about it? This is the strong headed attitude what we need.