PARALLEL IDIOMS

The definition I find for "get up (stand) on one´s hind legs" is to become angry and assertive, as in: “Campbell Coyle stands up on his hind legs and explains why it is not an act of rebellion to attempt to get rid of our infirmities by prayer.” Pacific Medical Journal, Vol. 38, 1895. US. || “When John was accused of betraying a family secret he reared up (on his hind legs) and denied it fiercely.” George Meyer, The Two-Word Verb, 1975. US. 

For "tirar (echar) las patas por alto" we find the definition: "dar rienda suelta al enfado que se siente gritando o en cualquier format violenta." As in: “Y han decidido echar las patas por alto y crear un caos de todos contra todos, para no quedar como los únicos malos de la película.” El Mundo, 15/01/1995. Esp.

Both refer to the action of a horse when excited or frightened. Both idioms have developed independently with the same origin and the same meaning.