Here in the printer’s manuscript, Oliver Cowdery initially wrote “for the wickedness and their abomination”. Virtually immediately he corrected the the to their by inserting the ir inline (there is no change in the level of ink flow for the correction). Oliver frequently wrote the instead of the correct their; for a list of examples, see under Alma 27:23. The immediacy of the correction, plus the difficulty in this case of the phrase “for the wickedness”, argues that the original text read their wickedness, not the wickedness.
Summary: Maintain in Helaman 4:11 the corrected reading in 𝓟, “for their wickedness”.