Even though Tamara and Owen kidnap Henry, it’s possible Mr. Gold stands idly by while it happens, and so is guilty by omission. At the same time, Mr. Gold might be blameless. Maybe everyone on the dock jumps to conclusions, and Belle has to play mediator and prove to them that Mr. Gold is not at any fault.
That’s what I was wondering too. This may fit right after the bit where we see the Charmings and Regina running down the street, which I assume is when GOAT are taking Henry through a portal by jumping off the dock. Perhaps they arrive and find Rumbelle there, and there’s a bit of a “what did you see and why didn’t you stop them” situation.