Optional rule: Escape from combat

Heya,
I have a question regarding the optional rules for being able to escape from combat.

The rule state that a leadership test has to be made to be able to escape from combat. If this leadership test is failed, the model is treated as fleeing.

Living rulebook, part 3 - p. 117 wrote:

Escaping from combat
Warriors that are engaged in hand-to-hand combat at the start of their own turn may try to escape from combat during their movement phase. Such fighters are assumed to have realised that the odds are against them and decided that it is just too dangerous for them to continue.
Declare which of your warriors will try to escape from combat at the start of your movement phase, at the same time as you declare charges. Turn the models around to show this.
Take a Leadership test for each warrior trying to escape from combat. This represents his efforts to find the right time to escape. If he passes, the warrior can move up to double his normal Movement rate away from combat and the enemy he was fighting, in any direction.
If he fails, his opponent is allowed to make 1 automatic hit against the warrior who is trying to escape, and the fleeing warrior (provided he survives) will run 2D6" directly away from combat. He will have to take a Leadership test at the beginning of his next turn.
If successful he will stop, but may not do anything else during that turn. If the test is failed, he will continue to run 2D6" towards the closest table edge and must test again the following turn if he is still on the table.
If a warrior is charged whilst he is fleeing, the charger is moved into base contact with him as normal, but the fleeing warrior will then immediately run a further 2D6" towards the table edge, before any blows can be struck.

My questions is this: What if the model is immune to psychology? Does this model then negate the fleeing rule?

If immune to psychology - no, they cannot flee. In fact immune to psychology applies only to undead models and daemons from carnival of chaos. It's completely different to "crazed" (darksouls) and "fanatical" (flagellants) which allows them to auto pass any leadership tests...
Ok just checked "immune to psychology" rule:

Quote :

Immune to Psychology: ......... are not affected by psychology and never leave combat.

Ok, so if i understand it correctly undead is NEVER able to voluntarily escape combat, since they "never leave combat" even though there could be a strategic motive?

Exactly. They fight to the death

Bommer, I was hoping it could be possible to have my liche escape combat, take a hit if the leadership test was failed, and be able to throw spells from a distance while my zombies go tanking the SOB.

Stupid undead rule. ..

Thanks for the clarification