The "tacker" would have stood a better chance of actually making a decent tack if he/she had ground off the paint before trying to burn through it.
BTW, Ugly welded coupons can still pass the visual/bend test, provided they still meet the inspection criteria....I can't always fail it for ugly alone. Do I think that this person may need a little more practice? Yup, but if it passes the inspection criteria, how can you make him/her retest(unless the contractor requests it)?
That tack however is ugly and doesn't pass some of the AWS D1.1(08) Table 6.1 criteria provided it will not be incorporated into the final weld(per paragrah 5.18.1(2)...based on Item 2 weld/base metal fusion(mainly IMO because they didn't grind off the paint per paragraph 5.15), (possibly Item 3 Crater cross section but the weld size wasn't given in this post), Item 4 weld profiles per Figure 5.4, (possibly Item 5, but the weld size is not given for that weld in this post).