Question: heat equation doesn't like piecewise condition

Heat equation using piecewise conditions in Maple produce (unwanted?) oscillations at the transition.  Not sure if this is normal or a side effect of using a piecewise boundary condition in the equation?

I came across a slide presentation for the heat equation having Neuman conditions using a piecewise boundary condition and I thought I would apply the example to Maple.  The piecewise nature of the boundary condition in Maple causes oscillations at the transition point.  There were no oscillations present in the graph shown in the slide presentation.  A bug?  or perhaps the slide presenter modified his graph?

Here is the Example

Next, an example with different initial conditions and boundary conditions,
with K = 1, L = 1, the initial temperature distribution
equal to u0(x), and insulated boundaries. These conditions are
known as Neumann conditions.
ut(x, t) = uxx(x, t), for 0 0,
u(x, 0) = u0(x), for 0 ux(0, t) = 0, and ux(1, t) = 0, for t > 0.
• Where u0(x) is a piecewise function,
u0(x) = (x, 0(1 − x), 1/2

So, quickly setting it up in Maple

with(plots):
eq := diff(u(x, t), t) = diff(u(x, t), x, x)

u0 := x-> piecewise(0

ibc := u(x, 0) = u0(x), (D[1](u))(0, t) = 0, (D[1](u))(1, t) = 0:

sol := pdsolve({eq}, {ibc}, numeric):

p1 := sol:-plot3d(u, x = 0 .. 1, t = 0 .. 0.2, shading = zhue):

display(p1);

And the slide example image

Which one is right?  Or does Maple not handle them the same