The person who passed away his name was Milos so il just call him Milos in the details.
My father and Milos was went together in the boat to birds island for a swim. They got there line alhamdulilah after the swim when they were ready to leave Milos and my father got back in the boat to start it, it was a very windy day and the boat was moving towards the rocks Milos told my father after getting the boat started that let me jump in the water and push you backwards. Milos jumped in the water from the front side of the boat and pushed it back. Shortly my father heard some people shouting, as he looked towards Milos he saw that Milos was bleeding a lot he quickly rushed and put Milos in the boat along the way he called the brothers that were at the cottage to get the car ready to rush Milos to the hospital. Reaching st the cottage the car was ready and Milos was rushed to the hospital but along the way or at the hospital un fortunately Milos passed away. I wsnt there but this is to the best of my understanding and Allah knows best.
My father did not have any intention to hurt Milos or harm him in anyway Milos has been with us for more then 30 years and he know the boat more then us my father is still un sure and he does not understand how Milos got hurt.
Version 2 given after a week:
My father and Milos went to Birds Island in a boat to have a swim now it was very windy and the boat was going towards the rocks so Milos told my dad let me jump in the water to push you back. While my dad was reversing going back wards Milos jumped in the water from the front and my dad went to the other side to pick my auntie as he was going he heard people shouting he looked towards Milos and saw that Milos was bleeding a lot. My dad dint understand how Milos got hurt he quickly rushed and put Milos in the boat and rushed him to the hospital. But unfortunately Milos passed away on the way.
Milos has worked for us for many years mufti saab my dad did not have any intention to hurt Milos he is also very upset and does not understand how it happened.
In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
Since your father was neither directly nor indirectly involved in the incident, he will not be responsible. 
And Allah Ta’āla Knows Best
Safwaan Ibn Ml Ahmed Ibn Ibrahim
Student Darul Iftaa
Checked and Approved by,
Mufti Ebrahim Desai.
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العناية شرح الهداية - دار الفكر (9/ 77)
أن الضمان لا يلزم إلا على المتعدي