I read some local media because I happen to be Indonesian.
It was said in some of the existing reports, the attackers 3 of them were foreign citizens (not Indonesian citizens) and 1 had been identified as an Indonesian and until now the case was still being investigated because indeed as you said 1 Indonesian citizen was wearing a police uniform even though It's not certain whether it's really the police or not because it could indeed be a disguise.
Currently, there is some evidence that has been submitted, such as CCTV footage and several transaction records.
if you have already told other people the number of your bitcoins, you should make other reasons when people ask you about it again, crime can come from anyone and anywhere, so being suspicious is quite important.
It's not only limited by told other people of Bitcoin you hold, but other thing like: teaching someone about Bitcoin, wear a shirt or anything related with Bitcoin, submitting your KYC to online site, and installing many applications which can spy anything in your device.
It seems that when looking at the conditions from the victim's testimony, they were known beforehand because the perpetrators came to the villa where the victim lived and forced them to open their wallet by committing violence there.