Why Lawson wasn't penalised for flipping Gasly in Miami GP

Liam Lawson has avoided a penalty for clashing with Pierre Gasly during the Miami Grand Prix because his Racing Bulls suffered a gearbox failure moments before the crash.On lap five Gasly went to overtake Lawson into the Turn 17 hairpin and was hit by the Racing Bulls driver, sending the Alpine into a flip and landing partly on the barriers. Both drivers were OK but retired from the race due ...