Some thoughts on this - a lot of the time there is a way to let people down gently.

But there a lot of other places where the ball did get dropped: Halsin taking pretty much every friendly option at the party as an invitation is the first one. And then getting the "sorry if I came on too strongly" line was really annoying. Gale has too many romance triggers, most of them obvious, but not all. Not sure about the Wyll dance thing, did not check that out myself.

The game is also bad at showing when your status with one NPC blocks the romance with another one. For example, the casual fling with Lae'zel blocks the Shadowheart line about truly connecting and initiating the romance until you select the 'I am ending our fling' line with Lae'zel. It's fine that Shadowheart doesn't want to romance you for this reason, but since it is a player initiated the dialogue line should be there, she should just turn you down and telling you why.