Your bet on 4th st as you pointed out was bad, overall its what made you fold on the river. That bet as you know could have been called by any hand, this confused you on the river when two straights were made Though i do not now the exact odds
( some1 here should ), your odds that your opponent held 7,9 2,3 or even an over set ( the only hands that beat you ) are low enough for you to call. Wish I could figure out the math but making folds like that will hurt your long term equity. Good luck at the tables.