I didn’t go through it with a fine tooth comb but you’re right the SMART results look generally good (at least for this drive) with regards to bad sectors. I do see you have some hardware resets which could be indicator of controller or cable but resets sometimes just happen with normal operations. If this drive errors again then definitely check to see if these increase.
There is a TrueNAS forum which deals with SATA drive errors on LSI cards using the SAS3008 controller like the one onboard the HL15. There’s a specific firmware release from broadcom to address it. I provided this information in another post so check that out. if you feel comfortable updating firmware, I don’t think it would hurt. The firmware on my HL15 was quite a bit behind.