If the 'position' is not defined then you are making an assumption either way - the position is either after the last move is 'made' or 'completed'.
Either way I'd say it's more logical to assume it's after the move is made as it fits the other rules and doesn't require moving back of pieces for a legal move which is not in the rules.
The main decider is the position on which the end state of the game is to be judged when the time runs out, and since the move by White is legally 'made' even though it is not 'completed' the actual position of the pieces on the board is legal and is the position? Is it not?
Do the rules define the position otherwise? Surely the position is the current placement of all pieces in which no illegal 'move' has been made?
In which case time runs out on whites turn as he/she has not 'completed' the move by pressing the clock and black has insufficient material so it's a draw.