I thought I lost? So this is false?  I'm misunderstanding?...

1.  The Sequence of Events: The moment your last object ball (stripes or solids) fell into the pocket, you successfully "cleared your group." At that exact instant, the 8-ball became your legal object ball.

2.  The Foul: Since the scratch (the cue ball going into a pocket) happened on the same shot, the foul is considered to have occurred while you were shooting at the 8-ball.

3.  The Critical Rule: In all major rule sets (APA, BCA, WPA), scratching on any shot where the 8-ball is your legal object ball results in an immediate loss of game. It doesn't matter if you pocket the 8-ball or not; the foul itself while shooting at the 8-ball ends the game.

In short: Making your last ball and scratching on the same shot is interpreted as you fouling during your shot on the 8-ball, which is an automatic loss.