Speaking of ‘calculated’, this segment in itself looks like it could be too- it’s so on-the-nose it even details a bit about Ouma’s brain and its capability, ending with him hardcore baiting Kaito into punching him. Thereafter, he isolates Kaito, saying that he would be trouble if he was ‘left to run around’.
Except there was ultimately more he wanted from Kaito than that.
Bear in mind that when we’re shown a greater extent of the talent later, it’s through Kaito pulling theatrics on us, via the Exisal. So what we’re seeing here could even be another cooperation between them, with Ouma dropping a few key phrases for Kaito to react to, and steer the conversation into a kidnapping.
As for ‘key phrases’? Rewind for a bit...
...and you’ll see something similar could have already happened in the past, with Gonta getting a ‘lightbulb moment’ at the words ‘kept watch’. Whether Gonta was aware of this or not is hard to say, but it is interesting how these two were cooperating some time before, and Gonta makes a big show of saying how Ouma ‘should be watched just in case he does anything weird!’
The matter is, cooperation with Ouma would have to be secretive, and the logical way to do that is to put on airs that there’s more distance than there actually is. Which, naturally, would involve Gonta playing up his ‘dumbness’ to play along with the ‘manipulated pawn’ shtick (and he does indeed do this after strangling Miu- ‘will this board break?’)
Finally, bear in mind that what Ouma and Gonta are keeping a lid on is the secret of the outside world, so if the game’s end is not what it seems... then it follows that there may be more layers to the overall commentary, too!