Could have gone for T12, where a single (12) would have still given him 170. Or T15, where a single 15 would have still left 167. Or T18, where a single would have left 164. Or single bull to leave 157, but that's of course much harder than hitting anything within the 12, 15 or 18 (preferably a treble, but a single in one of those three would have at least left a finish)
No way I can count fast enough to do that But a professional player really should have all of these routes firmly in their mind. Of course, huge pressure and all, so he can be forgiven, but it's a mistake nonetheless.