In your buddy's case where he bugled first I would say the bull probably positioned himself between a perceived threat and his girls, so not so weird in that case.
I don't think there's much else could have been done. At last light moving in to the timber just robs you of that much more light to count by with the added peril of being busted by one of the cows. Sometimes bugling the opposite direction and moving away will drag a bull with you, but in this case I doubt this guy would leave his girls, or the safety of the timber. Just another one of those plays that keeps you coming back for more