Nothing, and considering I, myself, am left-handed...
left-handed compliment:
Also, backhanded compliment. An insult in the guise of an expression of praise. For example,
She said she liked my hair, but it turned out to be a left-handed compliment when she asked how long I'd been dyeing it. This expression uses left-handed in the sense of "questionable or doubtful," a usage dating from about 1600.
left-hand·ed (adj.)
4. Of doubtful sincerity; dubious:
left-handed flattery; a left-handed compliment.Source: Dictionary.com
Even though that definition had backhanded compliment as another word for it, there appears to be
no definition for it... And the definition of backhanded is:
back·hand·ed (adj.)
2. Oblique or roundabout:
a backhanded compliment.The term "left-handed" seems more fitting, looking at those definitions, even if "back-handed" is more "acceptable." Political correctness is pointless. If someone's offended by that, they're too sensitive. "Left-handed" used that way could have "offended" me but it doesn't. It's not an insult. More ironic is that I USED the phrase myself. ;P