fuel cell questions

Well after consulting my book on how to remove the filler tube. I removed the screws in both the quarter panel and the grommet on the trunk floor. And it said to twist and use lubricant if needed. So I hit it with a few shots of lube and started twisting it back and forth. I’m thinking that the metal around the tube was fatigued and gave out because I heard a crunch and then I started cussing. So I cut the filler tube with sawzall then dropped the tank and seen what I had done. The metal around where the filler tube goes in gave way and was all broke up and cracked. And yes this was all with my bare hands