Clip 1 - 1 March 2018 - Law 19
It does happen. Here is proof that it does happen, and it happens even at the highest level.
In the very first scrum of the match, Ali Price of Scotland puts the ball into a scrum and his side gets a quick heel, but the referee awards a free kick to Wales because the ball was not put in straight.
The replay tells just how crooked it was, going straight to the Scottish locks.
The amendment to the scrum law reads:
The scrumhalf must throw the ball in straight but is allowed to align their shoulder on the middle line of the scrum, therefore allowing them to stand a shoulder width towards their own side of the middle line.
He is allowed to stand nearer to his side of the scrum but from there must put it in straight.
There was a lot of talk about this in the lead-up to this match and not putting the ball in straight in this situation was irresponsible indeed.
Scotland had a scrum six metres from their line. It became a Welsh scrum six metres from Scotland's line, and Leigh Halfpenny scored a try.