Hey Andreas,
I wouldn’t take any hose connections at all where I have to worry about something like that. As far as I’ve heard, there are problems only with the hose connectors on those cheap Chinese spindles or people clamping their spindle to death in the spindle mount until the spindle housing cracks and the water leaks out.
My spindle has the Festo QS8 tool-less hose connectors and Festo hoses, so I sleep easy.
I have no experience with the no-spill quick disconnect fittings Daniel @PwnCNC offers, maybe someone has?
The pump will pump liquid into the hose as long as there is liquid in the tank.
If you have a cooling station with flow sensor and the flow collapses, it can send the VFD an alarm signal which will stop the spindle (and the g-code program if wired to CNC controller correctly)