Why in the world would obtaining a Snowflake employee’s credentials allow you to then obtain Snowflake’s customers’ data? Doesn’t this imply that people working at Snowflake can see all of the data that I put in it? Admittedly I don’t have much experience with Snowflake, but as a baseline I expect better from a “cloud storage giant”.
Looking at linked-in, the unlucky employee could be someone in a sales role, with only 7 months of tenure. Every company has a few sysadmins with a scary amount of reach, but that's not what happened here.
Edit: A ServiceNow access request flow with poor internal controls would explain it.