The teams are about even as they untangle the knots, and the women are just slightly in the lead in freeing the machete. Shawna takes possession of it (Ferris Bueller chorus: "Shaw-naaaa..."), and she whaps it into the rope against the corner post to try to free the board. WHAP! Dave takes the Tambaqui machete and chops a rope, but he chops the wrong one, so as the women finish the chop and move to the next step, the guys don't even have the right rope cut yet. Dave takes the machete again, but either because of the shifting that they did by cutting the wrong one and trying to move the board without freeing the knots, or because he's just not doing it right, he has totally the wrong angle on it, and winds up trying to sort of pick at the knot with the tip of the blade rather than chopping through the rope. You can see at one point that he tips the blade up so that it's at about a 45-degree angle to the ground with the tip facing down and jammed into the knot, so the Pythagorean theorem (your second best friend in all of mathematics, according to Miss Alli's Mom the math teacher) would suggest that he has enough slack to drop it flat and use the blade to cut the rope rather than picking at the knot with the tip. The women move along with their key retrieval while the guys saw relentlessly at the rope. Actually, although you can't see this except with freakish slow-motion review (which is, after all, what I'm here for), the guys are at one point not even moving the machete, but are holding it still and Alex is sawing the rope along it, which is completely not going to work. Sawing is not what machetes are for. Just as the women approach the finish of the whole challenge, the guys finally get that rope cut. But the women throw open their escape hatch, and it's over. That's four out of five challenges to Jaburu, for those of you keeping score at home. It's interesting, the variety of types of challenges at which the women have, thus far, managed to emerge victorious. This time, they basically executed the whole thing perfectly, so the guys' delays in picking the wrong knot and then picking the wrong way to approach it were enough to finish them off.
When Peachy hands over the immunity idol, Deena makes a point of handing the blue feathers back to a humbled Rob. Heh. Peachy somberly tells the fellas to get back to the fraternity house and pick somebody to receive the boot.