Freelander 2 (LR2) 2007 - 2.2 TD4 130,000 miles

Hi again guys! My Freelander 2 is still bringing me joy! I have been told that I need a new engine!!! I was hoping I could ask you guys if this all fits before I go down that route. So long story short car has been off the road for about 2 months with an un-diagnosable "turbo flutter", engine man light and reduced engine performance. After changing all hose, air intake pipe, intercooler and new turbo actuator I got rid of engine man light but not the turbo flutter!!! so I went to put her through MOT and just before she was due to go in, my mechanic rang me and sent video. He said, " mate, I think your belt has ether jumped or snapped!, I believe that a piston has collided with a valve. now do you want me to spend 5-6 hours replacing the belt and see if that works (which i don't believe it will long term) or do you want me to put those hours towards replacing the engine?!?" .... now, since then he has said that the belt is intact but a little loose.... he then claimed that he was manually trying to turn the engine with a bar and it goes round, meets resistance and stops, he can go past this point but has too throw it harder to go round. there's one fundamental thing that is confusing me. Am I right in thinking that this engine wouldn't even run if the timing had slipped to the point of damaging the piston and valves?! Has he miss diagnosed this? Is there a possible solution that would tie in with the turbo flutter?? Now obviously I don't expect miracles with nothing but a video but any suggestions would be massively appreciated!! I intend to go the car tomorrow with another mechanic who has suggested to visually check the timing positions of the cams..

I would check the timing belt first to see if it's correctly fitted then take it from there.