Who knows, but it's definitely the wrong color for blood. They really screwed up on the fake blood here.

To answer some of the questions:

Why is the blood bright red?


Arterial blood is the oxygenated blood in the circulatory system found in the lungs, the left chambers of the heart, and in the arteries.[1] It is bright red in color, while venous blood is dark red in color (but looks purple through the opaque skin). It is the contralateral term to venous blood.

This blood stays brighter red even when it dries.


Why didn't he 'Bleed Out'?

Jeff lost his legs below the knee, therefore the Femoral Artery wouldn't be damaged, just the much smaller 'superficial artery'

The femoral artery (Latin: arteria femoralis) is a large artery in the thigh. It is a continuation of the external iliac artery and begins at the inguinal ligament (femoral head). In this segment, it is also called the common femoral artery (arteria femoralis communis) and gives the deep femoral artery, which provides blood to the thigh. After the branching of the deep femoral artery, it is called the superficial femoral artery (arteria femoralis superficialis) in clinical parlance, because of its superficial course. It continues along the femur to provide blood to the arteries that circulate the knee and the foot and enters the adductor canal. After it emerges from the adductor canal through the adductor hiatus, it is named the popliteal artery.[1]


Hypovolemic Shock

Direct loss of effective circulating blood volume leading to:

A rapid, weak, thready pulse due to decreased blood flow combined with tachycardia
Cool, clammy skin due to vasoconstriction and stimulation of vasoconstriction
Rapid and shallow breathing due to sympathetic nervous system stimulation and acidosis
Hypothermia due to decreased perfusion and evaporation of sweat
Thirst and dry mouth, due to fluid depletion and
Cold and mottled skin (Livedo reticularis), especially extremities, due to insufficient perfusion of the skin
The severity of hemorrhagic shock can be graded on a 1-4 scale on the physical signs. This approximates to the effective loss of blood volume.



Vasoconstriction
is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in staunching hemorrhage and acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus, retaining body heat or increasing vascular resistance. Cutaneously, this makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.