An update: Looks like this live stream used 4 DSLRs:
http://youtu.be/4XfcyOlMxAQ
I am not sure what cameras are being used here, but if I were to guess, one of the cameras is a Sony Cyber-shot DSC-RX100 III because it has a clean HDMI out and the back screen and buttons are placed in the same areas. The other cameras look like Panasonic GH4s or Canon T3i-T5is. The cameras are most likely not recording internally due to heat issues. They are just in live mode.
