Rabbi Jonathan Sacks, z/l: Vayikra -The Dimensions of Sin

The parashah addresses the chattat—the sin offering, which varies by the particular individual, for sins that were committed inadvertently. A contemporary example would be answering the phone on Shabbat because you forgot that the day was Shabbat. Today, such a sin is typically not viewed as such. He continues with another example: you are caught driving 50 mph in a 30 mph zone, although you know that your speedometer is inaccurate.