My 18 year old son worked seasonally for a garden nursery for four months last year and was just hired on again in March 2018 to work for the summer season. He worked twelve shifts, and then during one shift his supervisor had him lifting very heavy rocks out of bins and onto tables (fully bending over so not able to lift safely or properly). He sustained a groin injury. He went to emergency and had ultrasound. Before the results were obtained (turned out to be just a pulled muscle), he presented his employer with a doctor's note as he had to miss four shifts to recuperate. Upon returning to work, he received a letter indicating that due to a shortage of work he would be laid off from seasonal employment. Do we seem to be justified to pursue this as a wrongful dismissal?