While calling down with a draw is fine, we must pull the trigger on the river when our range gains a massive nut advantage on the flush-completing card.
Folding is the preferred play here. While we have backdoors, our specific combo lacks a spade, making it a weak candidate to continue against a range that hits this King-high board well.
Note: Calling with Queen-high and no direct draw is too loose; we should fold and wait for better spots to contest the pot.
Once we see the turn, the Jack is an excellent card for our specific hand, giving us an open-ended straight draw and a gutshot.
This is a major missed opportunity. The river 7s completes the spade flush and several straights, favoring our calling range significantly more than the opener's range.
Note: Checking back the river is a mistake; our hand has zero showdown value and functions as a perfect bluff candidate to fold out Villain's one-pair hands.