Guest, kudos to your teacher for making you dance a full spin turn along the side of the room. Many take the easy option of putting the spin turn in a corner as less turn is required. The problem is that this goes into muscle memory as the default action for a spin turn which then tends to be underturned everywhere and it becomes awkward to make the full amount of turn when needed, let alone an overturned version.
I'm afraid your explanation confused me as I was not sure where the corner was, so let me elaborate on my earlier comment.
Consider a typical beginner routine of repeated natural turn, change step, reverse turn, change step (different teachers will have a favourite starting point in this cycle). When danced near the beginning of a long room, the natural turn (6 steps) will end facing DC which may also approximate to facing the physical centre of the room which is why we need to be clear about what we mean by DC. There is now plenty of room to continue the routine with change step and reverse etc.
Eventually we get close to the corner. The full natural turn still ends DC although we are now long past the physical centre but there is now no room to continue with the change step and reverse. The usual approach is to turn the corner by underturning the natural to end DC on the new LOD. This can lead to the pupil turning the corner too early, potentially impeding the couple behind them. We can minimise the early turn by ensuring the first step of the natural turn is taken into the physical corner rather than DW which is possibly what provoked Phil's original question.
Another approach is to recognise that the full natural turn to end DC (side 1) is also now facing DW on the new LOD (side 2), so we can continue straight into another natural turn having effectively turned the corner.
I refer to side 1 & 2 above only for clarity as I try to wean my beginners off routines as soon as I can and encourage them to decide for themselves which figures to dance next, based on where they are in the room, which way they are facing and which foot is free to move.