correct me if i'm wrong,was the blind up in a tree??if so this was your first mistake.calling coyotes from up in a tree is about as productive as calling turkeys from a tree.if they were going with the wind and the wind was in your face then they shouldn't have winded you.your right you may have spooked them going in or by calling from in the air it made them a little more cautious on there approch and when you blew the second series they senced something wrong and spooked.or it may have been as simple as waiting the ten min between calls.you may have gotten there attention on the first series and they came in fast.when they got there they didn't hear anything or see anything so turned and continued what they were doing.or its possible that the tracks were older then you thought and you didn't call anything in.don't wait so long between calling sequences and keep your eyes peeled for any movement.if movement is noticed(remember a coyote will come as far as he can under availible cover before exposing himself)switch to softer coaxer calls.i would recomend not using the blind(wheather its in the air or on the ground)again.if you did spook them from that blind,its unlikly that you will call them to it again.try calling from the opposite side of the area.coyote huntin is a ficale business and unless you do something obveous to spook them its hard to figure out why they do what they do sometimes.