Sounds like the shot I made on my heshe deer earlier this week. You actually hit a little lower and further back than you think, or he appeared to be broadside but was actually quartering towrds or away, more than likely away. Mine reacted the same way, but didnt really tuck its tail. it flickered its tail, but the only difference was my exit took out part of the heart and there was no tracking needed with the amount of blood butI sat still and watchedit as he walked away and layed down. I gave him a good 1 1/2 hours and foundit dead.