Agreed! The only risk is that if you did release a massive amount of helium in an enclosed space, it could displace enough oxygen to drop the O2 concentration to dangerous levels.

That's why it seems like oxygen concentration monitors are a good idea for hospitals with liquid He. They don't really need to monitor helium levels since that's not the direct cause of problems. It's only an issue (but a big issue) if there's so much He released that it displaces enough air to meaningfully dilute O2 concentrations.