I build cryostats and operate superconducting detectors - I've been handling liquid cryogens for over twenty years.

I've stuck my hand in liquid nitrogen hundreds of times.

The main danger from liquid cryogens is the displacement of oxygen from the area when it flash boils.

While small amounts of liquid will skate around on a vapor barrier (leidenfrost effect on solid surfaces), in volume, the boiling at the interface between water and the liquid will produce some amount of turbulence and mixing that increases heat transfer.