According to critic Eric Deggans, the actor fell into this uncovered part of the pool at the HBO post-party at Circa 55 Restaurant at the Beverly Hilton Hotel.
"At HBO’s Golden Globes party," he tweeted. "Believe I just saw Milo Ventimiglia from This Is Us slip and fall into the pool, which is mostly covered but open in one spot..."
Milo later confirmed the pool-fall in an Instagram story featuring his damp (somehow still marvelous) hair.
"And yes I fell in the pool" he dryly signed off.
There's no CCTV footage to back this up, but we all know what really happened...