Ursa Mini Pro auto-record to SD after CFast cards are full

I've rent Ursa Mini Pro. I had 2 CFasts & 1 SD card plugged in while recording. I can't find all the footage I've recorded (missing equivalent to 1 full card). I'm pretty sure that I didn't switch the button to record to SD card. I've asked guys who rent me the camera if there is any material on the SD card that I've returned & they said there is not. I'm a little sceptical because I've said to them that I will rent the camera again, because of the lost footage. Maybe they lied to me, because of it. So my question is - if all the CFast cards are full, does it automatically record to SD? Or is it impossible?

No, it will switch from one CFast card to the other, or from June SD card to the other SD card, but not between CFast and SD card, as you need to use the physical,switch to change from one type of medial to the other.
DS