https://www.revenue.alabama.gov/faqs/who-must-file-an-alabama-individual-income-tax-return/

"Nonresidents must file a return if their Alabama income exceeds the allowable prorated personal exemption."

If the only income your AL non-resident has is a 1231 loss, do they have a filing requirement?

If your guy has an AL filing requirement, judicious entries into the Dispositions screen, such that the loss ends up in Column E, might solve your problem.