Post #1: "I was called daily to pick him up from school and not provided with alternative learning environments or other options. The school kept me on the waiting list to receive an IEP for the entire school year."
Post #13: "If he had so much trouble leading to the incident indeed an IEP would have been requested. He was 4 at the time and had not had a diagnosis or any behaviors constituting an IEP at the time this took place."
Post #15: "... he was removed that day when I discovered he was detained in the bathroom. He has not been back and I have moved and put him into therapy since then."
Post #15: "He had no problems constituting an IEP or 504 plan at the time."
Also Post #15: "At 4 he was diagnosed with ADHD but not Autism yet."
In the original post, you state that the school had him on a waiting list for an IEP for an entire school year, yet in posts #13 and #15 you state that he had nothing that would tend to lead to a need for an IEP or accommodations under a 504 plan, even though you state (also in post 15), that he was diagnosed at age 4 with ADHD but not Autism YET.
You also state in post #15 that you removed him (permanently) from the school the day the you were made aware of the incident, so it's clear that you didn't wait for a year after it occurred.
There are inconsistencies in your account of the matter that make it difficult to really follow what's going on. I hesitate to comment on the cause of those inconsistencies and I will give you the benefit of the doubt when I say they are likely unintentional. You may wish to review the facts and timeline of your matter when you seek out professional legal help.