Neither 'like stink' nor 'die like a pig' are necessarily insulting in use with reference to persons, although dying like a pig is clearly something to be avoided.
The first, 'like stink', is a common colloquial idiom with sufficient longevity to appear in two McGraw-Hill sources (see below) as well as OED Online:
Inf. rapidly. (As fast as a smell spreads. *Typically: go ~; move ~; run ~; swim ~.) Those kids moved through the whole test like stink. Real eager-beavers. The wood chipper went through the brush like stink and turned it into a small pile in minutes.
(McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. S.v. "like stink."  Retrieved August 11 2016 from http://idioms.thefreedictionary.com/like+stink. A similar entry appears in McGraw-Hill's Dictionary of American Slang and Colloquial Expressions .)
Note that the examples presented in the McGraw-Hill sources are neutral, at worst, and positive otherwise. The neutral-to-positive sense range is corroborated by the OED Online attestations:
b. like stink, furiously, intensely. Cf. like adj., adv., conj., and prep. colloq.
1929 R. C. Sherriff Journey's End I. 40 If you see a Minnie coming..you have to judge it and run like stink sometimes.
1938 M. Allingham Fashion in Shrouds xv. 240 It's raining like stink.
1945 ‘P. Woodruff’ Call Next Witness ii. v. 114 He clapped in his heels and rode like stink.
1955 M. Allingham Beckoning Lady iii. 40 The telephone's here..and when it rings you have to run like stink before the caller gives up.
1972 D. Devine Three Green Bottles 11 She wasn't really clever, she just worked like stink.
["stink, n.". OED Online. June 2016. Oxford University Press. http://www.oed.com/view/Entry/190407?redirectedFrom=like+stink (accessed August 11, 2016).]
The second, 'die like a pig', is a tougher nut to crack. It also is a common idiom, but doesn't appear in standard lexical sources. The colloquial idiom does, however, appear frequently in, for example, song lyrics. The sense of the expression ranges from 'to die stubbornly, reluctantly, while engaged in futile resistance' through 'to die by being slaughtered'. It's negative in that dying is not desirable, yet dying reluctantly, or being slaughtered, may be unavoidable in some circumstances.
As an expression of the facts of a case, 'to die like a pig' need not be personally insulting. The use by the sportscaster was such an expression. The choice of 'pig', however, was unfortunate; 'pig', while not necessarily insulting, is in isolation (that is, sans phrasal context) most frequently used insultingly when used with reference to persons. Likewise, but to a lesser degree, 'stink', although the phrasal context and history of use of the phrase strongly indicate that 'stink' in the sportscaster's use is admiring, rather than insulting.