When a person sinks the last coloured ball plus the white ball, while the black ball is remaining, is that game over or does the opposition player gets one shot on the black from the baulk line?
Officially, the game is not over if the 8-ball is not sunk, and the opposition player gets to shoot next. However, this varies significantly between regions, and in many locations the game will end. See link:
If the player knocks the 8 ball off the table then the player loses the game. If the player pockets the 8 ball and commits a foul or pockets it into another pocket than the one designated then the player loses the game
Otherwise (i.e., if the 8 ball is neither pocketed nor knocked off the table) the shooter's turn is simply over, even if a foul occurs. In short, a World Standardized Rules game of eight-ball, like a game of nine-ball, is not over until the "money ball" is no longer on the table.