布尔的奇怪行为

I have a function

func (ba * xxAPI) GetID() (newID boolean, err error) {
    ...
    newID = (ba.RateID == rr.RateID)
    fmt.Printf("old id : %d, new ID %d, update flag %v
", ba.RateID, rr.RateID, newID)
    ...

Which results in the following message :

old id : 325041, new ID 325041, update flag true

I wondered if it was the assignment and tried the evil version:

if ba.RateID == rr.RateID {
    newID = true
} else {
    newID = false
}

but (thankfully) the result was the same.

I am obviously overlooking something.

Any idea what?