No start and restricted performance issue, can see crank turn

Started to change out 2nd tensioners, removed cam caps and found passenger side cam was stuck and would not move, since tensioners looked really good, decided not to change and research stuck cam. Nothing moved on cam and I did not remove driver side valve cover, put everything back together, researched stuck cam and found that oil tension could be why cam would not lift out. Thinking nothing changed since car ran last, I started car, it ran for only a second and died, on restart, saw restricted performance light and car would not start. No noise or metal sounds were heard. No fault codes were registered. What happened and is motor shot? Local Ford dealer looked at it and said motor trashed, but I don't know what he did. Could stuck exhaust cam on start up, damage valves or what?