Gensler Entry Level Interior Designer interview questions

Referral through a Gensler employee. I interviewed with two directors who were very tired, therefore I mainly presented my work, and didn't feel pressured during the interview. They asked casual conversation questions, portfolio questions, then salary expectations. They said the HR would contact me in the next few days. After 5 days or so of not hearing, I contacted them. Then the HR called me while multi tasking on other things, quickly explaining the offer, also not having a full understanding of my background. I thought this was unprofessional and disappointing for a company with Gensler's reputation. Though I eventually negotiated slightly and accepted the offer. I always remembered the HR's attitude now as a sign of how corporate treatment can feel.