Is it my bad and how should I follow up with this contact?

I just got off a telephonic informational interview with a Singaporean alum who is an associate director in the corporate finance division of a big 4 company. I e-mailed him late last week and he responded right away, which gave me the impression that he would be really helpful. But unlike the informational interviews that I'd undertaken previously (which often took around 30 mins), this one lasted around 10 mins only. The questions that I asked were pretty standard: his current role, types of deals, required skills for a new hire, how to approach the application process, advice for me to leverage my experience in operations consulting, etc. Since this was the first conversation between us, I didn't wanna drill too deep into the job-application-related topics and appear to get to him just to ask for a job. Thing is, his answers were really curt, and despite my efforts to ask open questions, 8 mins into the interview, I already exhausted the questions that I typically bring to the table, and the interview ended really quick. I am wondering whether it was my akwardness (and surprise given his brusque responses) that killed the interview or he just was not in the mood for a chat?

I'd talked to several American alumni before, and they tended to be the ones who spoke while I listened and asked follow-up questions (and every now and then, they asked me questions,too!).

As I am just starting out networking with alumni and professionals, I figured that I'd better get it right in order to not waste useful contacts. What follow-up/open questions do you guys often ask to keep the conversation running smoothly and naturally (Please be specific if possible)? Any suggestions regarding how I should follow up with this alum?

Thanks a lot in advance