Someone came to the em forum not long ago to say something similar.
Edit: my response at the time is here:
Someone please start an academic discussion.
The long and short of it is that the ED is nowhere near as resource rich as other depts seem to think it is. If the OR asks for a non cutting spinal needle, they probably get it. The ED does not stock those, and if we want to go get one from upstairs we frequently get yelled at for touching things that don't belong to us.
Also, we review all of our bounce back cases to the ED. I can't remember the last time a patient who had an LP subsequently came back to the ED for a HA that ostensibly could be due to a post LP HA. That said, that obviously doesn't capture everyone.