SOT23-3 Pin out: IPC or Datasheet?
You ALWAYS use the manufacturer's data sheet. If it differs from the industry standard 'pin 1 in the top left corner, next to the index mark, increasing anti-clockwise round the package', then put a warning note on the schematic in text.

But first, does the part really have a non-standard pinning? Have you read the data sheet correctly? Have you confused a pins-up with a pins-down drawing? Has the data sheet been published with an error (it can happen). Check the pinning of some pin-compatible parts from other manufacturers, or contact the manufacturer. Once you are sure what the data sheet says, use that. I have had 'function' compatible parts that would work on the same footprint, with different pin numbers from different manufacturers, that required a table on the schematic to avoid confusing myself as well as others.

As in everything in life, the specific (data sheet) always supercedes the general (the standard).