The egress to the ISS from an EVA usually takes about 50 minutes on the schedule. The reason for this is simple, time is needed to get back to the airlock from whatever starting point and movement is slow as each ‘step’ needs to be precise. Then the astronaut must go inside and re-pressurize the airlock. Between going through all this and the different way that water reacts in zero gravity, the risk of drowning was quite real and very serious.
This occurred last Tuesday and thankfully the astronaut is fine and recovered. In fact he gave an interview the very next day reliving the entire experience. NASA’s ART (Anomaly Resolution Team) is investigating this mystery and to date has ruled out a number of causes, leaving the Portable Life Suport Unit and a number of its parts as the possible culprit. In the meantime, pending an acceptable outcome, no further EVAs will occur.
There is one thing that could necessitate an EVA during this period of a moratorium on spacewalk; if one of the twelve items at the ISS whose failure would render the ISS in a “zero fault tolerant” situation, were to become faulty or no longer work then NASA’s ART would meet to review and possible update the order. An example, the coolant leak of last May.