Not starting?

It all started a few days ago, when I realized my car was overheating seriously, I packed it for a while and filled it with water afterwards. On re starting it I noticed it still wasn’t fit to drive, I then drove it into a nearby estate and parked. I called a mechanic around to help check it. He said the radiator plastic too is damaged, the gasket is flat as well (I mobilized him to fix them all). When he finished, he coupled the car back and the vehicle did not start. He called his re wire to check (then said the starting censor was bad. I bought a new OEM, he fixed it). The car still didn’t start, the re wire said the four plug coils are damaged because there were no current passed to the plugs at all (I bought four coils). The car still hadn’t started. Now the mechanic is saying it probably has jumped timing or so. And I told him it’s his fault not mine. My car was working all well and good, I parked it myself the only problem was overheating. Please what could possibly be the reason for a vehicle as such to jump timing, and what is the best solution, please?