My daughter, SIL, and grandson were over today for dinner. I threw 2 of my last 3 backstraps on the grill. They were just a smidgen more done that yours, but still red in the middle and some blood on the plate.
They sat overnight in a mixture of red wine, worchestire sauce, browning sauce, black pepper, and garlic salt. Just before I put them on the grill I brushed them all over with EVOO. Heated the grill to 700 degrees using the sear burner and seared both sides for two minutes each (seals in the juices). Then cooked them on a lower heat for 12 minutes.
Though these are from October, today's results looked the same...