This thread is becoming a synopsis of spinal pathology - a large and rapidly changing area of medicine.
Most spinal pain does resolve spontaneously and indeed pure disc problems eventually settle as the disc dries out. However, in Germany where back pain is actively investigated with MRI and treated within days the number of sufferers returning to work is far far higher than in the UK where treatment is or has historically been conservative. Pilots have the additional problem of poor seating, cramped working conditions and long periods with dehydration. OP asked about the problems of long term pain and the advice was correct - get it investigated.
Personally I would always have an MRI. It is risk free and in the older person eliminates fractures and cancer. It allows early referral to a spinal surgeon who would not simply proceed to surgery for any abnormal finding. Indeed early local anaesthetic and steroid injections almost always are the way to go not surgery, but they terminate the acute pain and muscle spasm that so often results in long term absence from work
The red flags are loss of control urinating or incontinence and the same with bowels. These indicate the need for immediate referral.