we have commercials every 25 minutes

Yeah? I have mentioned that I haven’t seen the last two races, but this year I have seen – and noted – an ad break ending within 2 or 3 minutes of the start followed by another almost always at 10 past the hour (ie 10 minutes after the start of the race), with yet another on the half hour.
At the finish there might be one roughly 10 minutes before the end, roughly 20 minutes before the end, and roughly 30 minutes before the end, with another usually after the cars have finished which tries to coincide with the drivers getting out but ending before they get their trophies; if not then it will be between the trophy presentation and the post race conference – if the race has not over run and the switchboard is swamped with thousands of Corrie fans complaining.
In the early days ITV apparently tried to keep to a schedule for ad breaks – was there not an occasion when the finish was either missed due to a break or only just caught on the return from a break (I think that was what happened although I have not seen anything like this myself; it is just one of those things that people seem to remember)?

Flood.™