Infopass in LA on 485 case

EB2, 485 case inquiry.

PERM, PD 09/2005 RD/ND 07/13/2009, TSC

The officer is a nice old man.

- tell me finger print will be expired in Nov
- everything else is ok
- asked if name check cleared, the answer is yes. told me my case need an interview
- asked if a expedite request could be sent, answered yes, made copy of my driver license/ 485 receipt

Questions:

- is interview for EB2 common? what triggered the interview?
- does expedited service requuest works? the office said he will fax the request and I will receive response 30 days.

appreciate your response.