Did it have wrinkles under the armpits? (rossii). It could also have been mannifera, which usually has powdery bark, with white powder on your fingers when you rub it.
I was there as part of a FOG group and both Sue McIntyre and Marg Ning did a reccy of the area and no-one saw any mannifera. This tree was amongst a grove of other rossii. There are also no mannifera recorded on herbaria round Hall.