According to Wikipedia: "In the UK [spastic] can be considered an offensive way to refer to the disabled, while in the US it is more closely associated with hyperactivity or clumsiness and carries few offensive connotations."
And:
"The difference in understanding of the term between British and American audiences was highlighted by an incident with the golfer Tiger Woods; after losing the US Masters Tournament in 2006, he said, "I was so in control from tee to green, the best I've played for years... But as soon as I got on the green I was a spaz." His remarks were broadcast and drew no attention in America. But they were widely reported in England, where they caused offence and were condemned by a representative of Scope and Tanni Grey-Thompson, a prominent paralympian. On learning of the furore over his comments, Woods' representative promptly apologized."
So, although the word isn't used in a derogatory sense by Americans, it doesn't sound like it was a terribly apt way to describe Jill's reaction.
Learning what words NOT to use in a country you're trying to sell things to, is one of the first rules of business. (Mazda LaPuta, anyone? Spanish for 'wh0re'.)
Actually, I noticed Tova kept 'losing' her words. Perhaps the Botox has gone too deep...