"The doctor planned to send her home"

My mum who is in her 80's and has vascular dementia was sent to A&E by ambulance GP referral. She wasn't well with her chest and constant cough her oxygen sats were low. While in A&E we waited for 10hrs for a bed. I said to a nurse could my mum have tea and sandwich as she is diabetic, I was told they don't have any tea bags or sandwiches. The nurse gave my mum a glass of milk.

I told the nurse my mum had to go to toilet for a bowel movement and that she needed stand aid with assistance of 2, the nurse said we don't have a stand aid and that they could put a pad under her to do toilet. I wasn't very happy about this outside the cubicle my mum was in there was male patient who was heavily under the influence of drugs and another who was very drunk, I spoke with the Dr who was looking after my mum was told there's no beds, and that my mum didn't have a chest infection its her COPD. I said if my mums oxygen went up and stayed up can I take her back to her care home instead of her lying in cubical on a trolley, I was told this would be OK and that she's not got infection.

Short while later a nurse said it is a chest infection, her oxygen dropped again. Doctor then said mum couldn't go home that night. My mum was admitted to ward 46 then next night transferred to 35. She was on oxygen, nebuliser, steroid injection , antibiotic and kept in for 8 days in that ward. The ward staff were very professional and helpful with patients and relatives.

I want to know why the doctor would say that my mum didn't have a chest infection and planned to send her home. Was this because they needed the beds?