Who did he trash talk? No names were given. Divers need to break out of that silence is golden mentality. If you see bonehead instructors, please say something.You became a member and started a thread to trash talk someone.
You did the right thing contacting PADI with your concerns. If they closed their investigation, then it would appear that there is a disconnect in understanding what is happening.
Many shops offer a zero to DM. Most students feel that they "start" their training with the first class even though that's not the actual DM portion of the process. It's a pretty common misconception. I did the very same thing when I finally got certified. I think it took me two or three months and would never, ever recommend that instructor to anyone under any circumstances. I'm an adequate diver in spite of his less than competent tutelage.
SKILLS ARE MORE IMPORTANT THAN CARDS!!!
You and you alone are responsible for your competency or lack thereof. Just because your instructor is an idiot, doesn't mean you have to dive like one. Concentrate on your trim and neutral buoyancy and then work from that. There's a lot to learn right here on SB that will help close your knowledge gap. Carpe Divum.