If this is a habitual thing for the player then I would agree, start fighting back and put the pressure on him to figure out if you have it or not. The only thing I would caution you on is before you start to fight back you are going to need some information so you can augment your range in the most favorable way possible. What do I mean by this…we need to know what we think he is going to do in the face of the shove. If he has be open/folding to 3bets before then that is a great sign and I would start 3betting him very wide as I am not afraid of him doing anything. If he has shown a pension to raise/call or to not let a raised hand go, then we need to take that into account and adjust around what he has been raising/playing with. If you have seen him raise/calling and playing a lot of just hands from the button (Kx, Qx, Jx, paint+low rag type stuff) then I think you can be wide with your shove range here and include virtually all Ace-x hands, K-9+, Q-9+, J-8+ stuff because we can easily trap him with a dominating hand. If he has been playing stronger stuff, then I agree we still want to pressure him to make him start thinking twice, but we will need to tighten up our shove range to make sure that we are in the best possible situation if/when it goes to the felt. Also leveraging card removal here is going to be a big thing when trying to combine HUD stats with your impression. Don't forget to exclude or reduce holdings that you combat with your hole cards when making that estimation.