You are only allowed to move once when defending in Formula One, and Schumacher moved more than once on at least two or three occasions during the race at Monza.
The regulation is there for safety reasons, and to stop drivers from weaving.
I know from bitter experience what can happen when things get too tight at Monza.
The long straights usually produce close wheel-to-wheel racing and that is what we saw on Sunday.
It is important that the drivers give each other space as at such high speeds you can have a big accident if things go wrong at the Italian track.
That is what happened to me in 1997 when Ralf Schumacher, Michael's younger brother, misjudged trying to pass me in his Jordan, and put me off when I was travelling at a speed of 200 miles per hour in the Sauber I was driving. I remember he moved alongside me on the way down the start-finish straight towards the first chicane.
He kept on moving across on me and eventually we touched and it pushed me off. I spun across the gravel and hit the tyre wall very hard.
I was okay, and not hurt despite the big impact, but I do remember that when Ralf came to say sorry, he did it with a smirk on his face.
I was not happy about that.
On Sunday, his brother went a little too far in his attempts to keep Hamilton's McLaren-Mercedes behind him. There was one occasion when he went to the inside line then, as they began braking for the Ascari chicane, he moved across on to the racing line, and that is not on under the present laws.
The fact that Ross Brawn, the Mercedes GP team principal, was on the radio telling him to leave room told you that even his team thought he was pushing it a bit too much.
Hamilton was hit with a penalty for changing his line twice in Malaysia earlier this year while defending from Fernando Alonso, and you could not blame the McLaren driver for wondering why Schumacher did not receive punishment for going too far in his defensive driving.
It is motor racing, and Schumacher had every right to defend his position, and make things difficult for Hamilton, following a great start that had seen him go from seventh to third place.
But I do think on two to three occasions he broke the current laws. I am surprised the stewards did not bring him in for a drive-through.
Probably the most dramatic incident between the two was when Hamilton put two wheels on the grass on the curve following the first chicane as he tried to go up the inside of Schumacher.
In fairness to Schumacher, I do not think he did anything wrong on that one. Hamilton was a bit ambitious in trying to pass there, and Schumacher, whose back wheels were always in front of Hamilton's front wheels, was taking the natural racing line going through there.
I do not think that Schumacher knew that Hamilton was there, and certainly would have not expected him to be there.
Hamilton had to take evasive action, which looked more dramatic on television than it probably was, although it was serious enough to lose the Briton momentum, and allow him to be passed by his McLaren teammate, Jenson Button.
The other incident on Sunday that was a little close was when Alonso gave Sebastian Vettel very little room as the Red Bull Racing driver tried to pass him for the lead.
Alonso pushed Vettel as far left as he could as they went side by side on the drive out from the first chicane, and the Red Bull had two wheels on the grass as Vettel kept his foot on the gas and completed the passing move.
Alonso was a little tough with that move, but it was fair and, in my view, a racing incident.
Alonso made it as difficult as he could for Vettel, but did allow the German sufficient room to pass him and go on and win his eighth race of the season.
Johnny Herbert is a former F1 driver with three career victories. His column is written with the assistance of staff writer, Graham Caygill.