Well he might have some reasoning for not doing it, but everything I read about ear hematomas mentions it should be drained. An ENT already told me it probably should have been drained. I thought ignorance is not a defense? Or is there just too much grey area here to pursue?
There will always be grey areas and specific facts will always matter.
I think your problem right now is that you are asking the wrong people about the drainage of your hematoma. Our opinions here are no better than the opinion offered you by the ENT or the one offered you by the doctor you spoke to already. Whether you have a claim worth pursuing is unlikely to be answered by reading medical articles online.
And this is because, although many types of hematomas are drained first before compression, some aren't.
What I see as needed is a frank talk with your doctor about how he treated your ear injury. Ask the doctor
why he did not drain the hematoma. It is always possible that you will discover he
did drain it and you were just unaware of it at the time.
If after speaking with your doctor, what he says makes no sense to you, you can request copies of your medical records. You can either get from other doctors additional opinions based on your medical records and the facts of your injury, or you can find an attorney in your area who will look over your medical records and who will probably consult with a medical expert and who will be able to provide you with an opinion on whether you could have a supportable case against your doctor.
Only a doctor can tell you if the scar tissue and hardened cartilage could have happened anyway and if this is a known complication of your type of injury, with or without drainage. Only a doctor can tell you if the scar tissue and hardened cartilage can lead to additional problems for you later on. And only you know how much the scar tissue and hardened cartilage has affected your life. Only you know the extent of your damages.
I wish you good luck, anonymous88. I suspect you do not have a legal action worth pursuing, but I could be wrong.