Would seem that way. People like that don't do a lot for the rep of the trade. Pretty simple straight forward job if it was ever needed that is, but only IF you know what you are doing of course.
If the bottom chain has jumped a tooth neither the injection pump nor the cam shaft will be timed correctly. This can be easily achieved by turning the engine and therefore the injection pump backwards. Injection pumps do not like being turned backwards. Doing it can load the tensioner and lift it jumping a tooth. Excepting for a small jiggle to locate the timing pin these engines should NEVER be turned anticlockwise. He needs someone who knows what they are doing to look at it. No amount of speculation on here will sort it.