Depends on what type of cast iron was used. Ductile cast iron will bend some before breaking. Its what my rear diff cover is made out of and the reason its 3/8" thick and weighs 10 lbs.It's a cast piece, so it would crack more likely than "bend".
If you got the same measurement on both sides its a very slight bend if any at all and the first mechanic wouldnt have been able to tell just by looking at it. Hopefully you get out of this without too much money. Labor can suck though with new bushings. Cost me $500 labor to have lower bushings done on both sides and was told to never bring another isuzu in for bushings.