Ether will not damage your engine in small amounts. The key word is small. Putting too much in there though will cause trouble. There are ether assist systems built specifically for large diesels starting in cold climates. I have seen the timing belt jump a tooth or two with especially hard starting like what you experienced. Why don't you check your timing first before you panic? Injector checks like you suggest is a good idea too. There may be a stuck or blocked injector. It almost sounds like your fuel system froze with water. It's not the best for the injection system but only terminal over a period of time.
That's what i was hoping I wouldn't hear. I didn't disconnect them, but I made sure to heat them before spraying the fluid. They should not have been energized while there was ether in the system. Did you take your engine apart after it happened? What specifically was the damage?