Clarification on the whole "Who is the target of the attack"

[DanLeCull]

It is generally understood that effects like Sacrifice and Body Guard change who the intended target of an attack is as made clear in this post:

It is also generally understood that range and LOS do not factor in the validity of this new target, for example my character attacks your character but your body guard hiding around the corner of a large building  redirects that attack to himself where my attack conditions would normally not enable me to attack this character. Correct?

How is it that Trip Up behaves differently in this post?

The conditions for playing Trip Up were initially met (2 characters within R2), but the redirect from body guard/sacrifice changes the target of the attack. The second part of Trip up which is not only a different sentence but also a different paragraph, simply looks for the TARGET of the attack receiving damage, if THAT condition is met then I would argue that the effect of Trip up should apply.

Some clarification would be greatly appreciated here

[Negoldar]

1 hour ago, DanLeCull said:

It is also generally understood that range and LOS do not factor in the validity of this new target, for example my character attacks your character but your body guard hiding around the corner of a large building  redirects that attack to himself where my attack conditions would normally not enable me to attack this character. Correct?

Correct. 

1 hour ago, DanLeCull said:

How is it that Trip Up behaves differently in this post?

Trip Up is played during step 2c against the target of the attack at that time.

In the situation described, after Trip Up is played on the character that is the target, the defending player changes the target of the attack. 

Trip Up was played on the first character, not the second so its effect doesn’t move to the new target.