If I was the dealer I would tell the player I can't tell you what is in the pot so I don't know what you are betting. Hopefully he would then come up with a number and that would be the end of it. Of course with murphy's law in effect some player is likely to pipe up and say, he has to bet the pot. At this point I am done with it, there is no point to argue here, I call the floor for a decision.
If I was the floor coming over to make the decision, I would explain to the player that we do not count the pots in no limit games, the dealer, me and the other players are not allowed to tell you what is in the pot. If you know what is in the pot please go ahead and bet whatever you want based on that knowledge. If the player did not get it, I would explain it again. If the player just simply insisted we had to count the pot for him I would simply state it did not work that way again and tell him the decision is final time for him to act on his hand then I would walk away. If it went further then this I would invite the player to come talk to me away from the table.
If I was a player, rather or not I made an issue of this would be solely based on rather or not I want a pot sized bet from another player. If I was holding a big hand I would argue loudly that the player must bet the pot and the pot should be counted. If my hand was not so good I would dummy up and see what happens. Anything a player might argue here, whom is involved in the hand is very likely to be based on bias at this point. There is of course another type of player whom just like to argue the rules and we wish that player would STFU.
In the comments section of the post I referred to Lee said essentially he would hold the player to betting the pot, the other user arguing that it was not a legitimate bet. The comments section got a little ugly there, as they will tend to do when people argue which side of a paradox is the right side. Technically they are both right but it is a paradox so whatever is right is simply whatever works best at the time for someone.
I have not seen a rule that directly addresses this situation. If a rule was made I think it should be that saying I bet the pot in NLHE is saying nothing, IE meaning expressing a bet like that says nothing about the size of your bet. The reason I think it should be handled that way is because a player expressing a bet like that is simply angling the rule that says pots are not counted in no limit games. If you take the approach if saying the player has to bet the pot if they say I bet the pot, you have set precedence to nullify the rule about stating the size of the pot.
I currently work at a large Las Vegas strip casino with a big lake and water show in front which I am not a spokesperson for. Many players consider the poker room at this place to have an informal leadership role with poker rulings. I will ask around and see if this particular situation has come up and if so how it was handled.
I asked the shift supervisor were I worked. Said not a valid bet the player must come up with a number. Has only made the ruling once.