Ashley is correct. No offense, but what the other person is saying doesn't make any sense - or they not using the definitions of the words you are asking about.

(explicación en español después) A pretext is when you try to justify why you have done something, but the reason that you give is not the real reason. For example: the man stole the money on the pretext of being poor. (In other words, the man may not actually be poor. He stole the money for another reason.) An excuse is when you explain why something was done, but you are also trying to lessen the blame. For example: his excuse for stealing the money is that rich people already have too much money. (In other words, he is blaming rich people for his bad actions.) "Pretext" significa que uno está justificando por qué ha hecho algo. Pero, la persona no está diciendo la razón verdadera. "Excuse" significa que uno está explicando por qué ha hecho algo y quiere echar la culpa sobre otra persona o minimizar/eliminar su propia culpa. (Yo puedo traducir mis ejemplos de arriba, si lo necesitas.)

I am not sure I understand the question but I will try anyway. To excuse means to ask politely to do something. You may excuse someone from a meeting by letting them leave. My teachers at school would always get angry with me due to the fact I was always asking to be excused. I would make the excuse of needing to go to the toilet. Pretext can be broken down into two parts. Pre means before. Before the staff meeting I had a pre meeting with my boss to discuss the meetings agenda. Text is the information. The information in this text may or may not help you. So a pretext is the information you give before you have to do something. It could be good or bad. Good= The customer pretext the problem by telling me what she had been doing before the Iphone stopped working. Bad= I gave the pretext of the phone being an apple and therefore it would not be worth fixing. In fact it was worth fixing but I do not like Apple products so I sold her a Samsung instead. I hope this helps. Have fun