The former Grand Prix racervrevealed that he had wanted to black flag the seven-time world champion for his dangerous squeeze move on former team-mate Rubens Barrichello towards the concrete pit wall at over 180mph.
However, with the incident occurring so late in the race, by the time the stewards had received the video evidence their only option was a retrospective penalty.
“We interviewed Rubens and Michael and it was kind of disappointing how Michael handled it, and we had no option but to give him a 10-place penalty,” Warwick told BBC Radio FiveLive.
“If we had enough laps [we could have disqualified him] but you have to have video evidence and make sure all four stewards are in agreement.”
He added: “You could disqualify him from the next grand prix, or two grands prix, but we felt a ten-place penalty is a big penalty to carry for Spa.
“Hopefully he will learn from that and remember that the new stewards will not tolerate that driving.”
Schumacher apologised to Barrichello through his personal website on Monday on the back of calls from all corners of the sport for him to quit.
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