Well your boss really has two options either pull it out and do it the right way and either turn the whole crank or get a new one. Or just patch it up like they said and get rid of it.
There is no quick fix on this it has had a major engine malfunction so if your boss wants to keep it and have a dependable engine you will have to go through it again at least with the crank and new bearings if the liners and pistions are new just put new o-rings on them and rings and reuse them. but there isn't a cheap way to fix that crank and it be good to go. It really needs to be pulled out and totally disassembled then have than block deplugged and boiled out at a truck machine shop somewhere. If you don't all that metal from that one rod bearing is going to be pumped back through it when you put it back together again.
So either way its gonna be alot of work and money to fix it back right.