N52 oil in coolant

Hey guys, my father is currently on vacation with his e61 and it looks like he's not able to come back with the car. It started with leaking with the oil cooler hose, spilling oil and water all over the engine bay. The local shop replaced the oil cooler + sealants and we thought it was solved. On the way back from the shop, the car overheated and the coolant expansion tank exploded. According to the shop, the head gasket should be fine and most likely it has a cracked engine block. How likely is this and did anyone have a similar issue? Any other ideas? 180k miles currently. Appreciated!