I believe the standard strategy is to try again

By "try again", do you mean a while loop where you're attempting record.submit/save ( risking overwriting some other change) OR looping back to above the record.load, and reprocessing the entire record (substantial governance hit in my case) OR some type of field by field evaluation to determine what the "change" was? Is there any way to determine what changed the record? The system info is useless. It's not telling me anything updated the record.

once you have the record has been changed error, you can't just submit the record again

Okay. Thanks