Complex sentence: Pérez swerved to avoid hitting Rosberg who reduced his speed in the 13th and 14th turns for which the Mercedes drivers was issued with a repirmand by the stewards, while Gutiérrez was not penalised by impeding Massa in the same area.
Split into simpler sentences: Pérez swerved to avoid hitting Rosberg who had reduced his speed in the 13th and 14th turns. The Mercedes driver was issued with a reprimand by the stewards, while Gutiérrez was not penalised for impeding Massa in the same area.