That's good news.
But here's the thing: don't worry about the injection pump timing right now.
For a moment, forget about this immediate problem (which may well have saved your entire engine, by disabling it before other more serious things could go wrong), and instead focus ALL of your attention first on the FRONT CRANKSHAFT BOLT.
Why do we keep harping on this, even though it is not the direct cause of the truck not running right now and is NOT the question you asked about?
Because if your guy didn't have the tool or correct method to successfully tighten the rear camshaft bolt, then it is almost certain that he didn't have the ability to successfully torque the front crankshaft bolt either. Again, you should ask him what he did and maybe we'll be pleasantly surprised. But the answer is probably that he attempted to "get creative" with that part too.
If that bolt is anything less than exactly as tight as required, then it WILL come loose. The torque spec is about 350 ft-lb -- probably tighter than any fastener your mechanic has ever installed in his entire life, and probably almost DOUBLE the maximum value his torque wrench reads up to. Guys try to do it "by feel" or with a big impact gun, but that will not get them close. They also try to do it using the transmission to hold the crank in place, but that doesn't work either -- it will break the gearbox or slip the clutch before you reach the target value. There is no way to do it except with the right method and equipment. If the bolt does comes loose, then it will at minimum destroy the entire top end of the engine and usually the crankshaft also. Sometimes worse. It will be a very sad day not just for you, but also for your mechanic if this happens.
That's the warning. Don't start with the repair to get the truck running, even though it will be very tempting to begin there. Don't do it. First, get this part right.
THEN, proceed to have every other part of the front timing system and process double-checked again, this time following the factory instructions to the letter and using all the right tools. ALL of them. This includes cam timing, idler pulley installation, front camshaft bolt torque, etc.
Then, finally, once you/he are sure that the engine is not sabotaged anymore, proceed through the full injection pump timing process to get the engine running again.