I would guess that the logger is continually monitoring the line and that any dialling is picked up whether or not it is from the premises or not.
A BT Tech could have been working at the cabinet and tidying up cables or replacing a multipair cable which resulted in disconnecting yours for a few seconds. To check the correct pair was reconnected he could dial both those numbers.
So, nothing to worry about and no charges will be incurred.
M H C
taurus excreta cerebrum vincit