The CIS-E computer is "analog" (as opposed to digital). And perhaps this would allow backwards or upside down signals to do strange things? There is mention of a microprocessor below, but that may be something added as the years went by? (More and better fault detection - learning curve thing.)

Also I can imagine they would not initially think to test for such a situation because they would never imagine it happening.

So far as "implausible results" (term they use in the factory service manual and Bosch KE footnotes on this [barely mentioned anywhere]), I've not been able to find very much written on this, but from what I have read, mostly it seems to be open circuit, short circuit, or a sudden change in value / not possible [intermittent connection].

Anyway following are a couple of footnotes I've found on this. Keep in mind that the notes below may only apply to later year KE control units and some things mentioned may not have been implemented in earlier units???

A footnote on this...
[y) Emergency running (plausibility)
The signals supplied by the peripheral components
to the KE control unit are continuously analyzed. If
the composition of the signals is no longer logical, a
substitute value (emergency running property) is
formed automatically for the non-plausible signal by
the electronic control.
If, for example, a rapid change in temperature is
simulated - engine at normal operating temperature
and coupling of coolant temperature sensor then
unplugged, the microprocessor in the control unit
compares the momentary temperature with the
stored temperature. The control unit detects open
circuit (short-circuit) and programmes emergency
running mode. The control unit does not detect a
slow change in the characteristic curve
(characteristic curve drift).]


Another footnote...
[With the ignition switched on, the
input signals to the KE control unit are tested in the
static state of the components. The faults are not
stored and can only be displayed immediately (i. e.
only if the fault exists at that moment) by measuring
the on/off ratio at the diagnostic socket (X11). This
output mode can also be used for a rapid check of
the signals monitored in this case. For measuring
on/off ratio and fault table see Diagnosis Manual
Engine.

When the engine is running, faults which occur and
are recognized (e. g. open circuit, short-circuit and
implausible values) are stored in the KE control unit.
Loose contacts are also recognized as faults and
stored. The stored faults can be read at the test
coupling for diagnosis (X11/4) with the pulse
counter. A condition is that the battery has not been
disconnected in the meantime otherwise the stored
faults have been erased.}