Based on what I had found with my searches I was under the impression that using a backup was a last resort after attempting a repair.
No. The backup is usually the best approach. Repairing with the allow_data_loss option loses data. What data, I can't say without a lot more information, but checkDB's not particularly polite. It will discard anything that's damaged and patch up the rest. You could get all sorts of transactional inconsistencies and orphaned data from running CheckDB with repair allow data loss. Since sharepoint keeps the site structure in the database, you could end up with an unusable site.
I take you are recommending going killing the process that has been running and go to the backup?
If you have a good backup that's recent enough that restoring it is acceptable, absolutely yes.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
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