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 ...