What does "Interesting Assumption" mean?

[VorFemme]

I tend to fall back on my training and say, in a slightly amused tone, "Objection.  Assumes facts not in evidence," and leave them to try to figure out what the HECK I just said.  But this phrase is much, much better.  I shall use it.

But it sounds so much more like a line from a script for Perry Mason, Ben Matlock, or even one of the lawyers on Law & Order when you say "Objection, assumes facts not in evidence"!   "What an interesting assumption" and turning away from the idjit comes closer to giving them the cold shoulder, though.

Gee - they both have their appeal.........