Urgent care sent my son to ER but it wasn’t an emergency

Please let me know if there’s a better sub to post this in. We took my son to UC for a high fever. UC checked his O2 level and said it’s at dangerous level, tried to give him a breathalyzer, but it still shows the same. So they sent us to the ER. We went there, they checked his vital. They said besides the fever (from a virus, as UC found out), everything else is normal. After that they said we had to wait for a doctor to consider if they’d even want to see us? 3 hours passed by and now he’s being seen, just for the nurses to reconfirmed that he’s not in need of emergency services. They checked his vitals again twice. Now they left us all here to wait some more while they disappeared for 30mins. My concern is I know if we go to ER for non emergency things, insurance won’t cover it. But UC sent us here, would we still be billed for this visit?