Nearly had a horrible accident for the very same reason. Having indicated left I turned down this country road with a housing estate half way down on the left. Approaching the left turn into the estate a woman pulled out in front of me. I banged the horn gave the fingers and lots of verbals only to discover I was still indicating left, the bloody thing hadn’t cancelled. I didn’t see the indicators because of my hand position neither did I hear the indicator because of the radio. What a prick she must have thought I was No permanent clock display and the paint, well, were all aware of that one.
Still if you went into her it would be her fault. You never presume someone will be turning until they have done it