Received an InMail on LinkedIn asking to setup an in-person interview. Responded the same day with my preferred date/time for the interview. No response. Emailed back the day before to confirm the time and got a condescending voicemail commenting on how I "didn't respond for many days" and they were "actively searching" so could I "PLEASE respond with new availability". I chalked this up to her having a bad day, laughed it off and setup a new time.
The in-person interview was nice and professional. I met with their sales lead and the COO. I was told the next steps would be on-site interviews with a few other team members and then dinner with the CEO because they felt it was important to get a feel for culture fit. Sent some thank you/follow up emails and never heard from them again.
Common courtesy: If you bring someone on site, keep them informed (good or bad) of their candidacy... even if you aren't sure.