I've been in the team for a couple of years and about a year back, our team absorbed the responsibilities from another team which consisted of senior/very technical people.
For this process, there was a very huge amount of information to absorb but an extremely brief transition time was given by the management. This resulted in our team members burning out because there was a lot to absorb suddenly. Our team worked till midnights everyday for 4-5 months by resorting to trial and error mostly and figuring out their own solutions.
Now most of the team members have quit the company. I am taking on the responsibilities from other people and there's still new things for me to learn.
Now I have to ask a member from the original team. For example, when I forsee that a solution will work immediately but cause unintended consequences after a few months.
When I interact with this person, the one from the original team, then he always responds in snappy ways to my questions. He also takes a stance that these are very obvious things and gets angry in explaining about it. I try to explain that I'm taking this responsibility for the first time and that I'm going to ask them these questions only once because it's the first time for me. They respond back "that's okay" but still get angry with me and take up the same stance again.
I also find it rude when they behave in a similar manner in team meetings by speaking to me in a condescending manner.
How do I deal with this senior person who's behaving rudely towards me, especially in front of the whole team?