Gotta love Spurs coach Gregg Popovich.
This is not that uncommon by the way — NBA head coaches are not the ones directly scouting each opponent during the season. Teams have advanced scouts, video editors, plus the assistant coaches usually divide up the opponents and break down the film. The head coach may watch some film and reads the reports, but he’s not the one that does any in-depth study of a team. Not before the playoffs, anyway. (Phil Jackson used to keep one team for himself and do the scouting when he was head coach, just to keep a toe in the water.)
That said, most coaches when asked those kinds of questions give some vague answer based on what they read/saw. Popovich just doesn’t want to play that game.
Next time I see Popovich pregame I may ask if he prefers scalene or isosceles triangles.