Not sure I buy it. The limits here are more 'go talk to your boss' than 'stop bidding when it gets to $XXMM' for everyone involved except for Deepmind (which was later also bought by teh googs).
Furthermore, execs are creatures of emotion and whimsy, rather than strictly rational operators. As the price soars higher, they see that everyone at the table values the thing highly, and are likely willing to increase their max bid as their sense of FOMO increases... Subincrements aren't going to matter much, except to ratchet up the feelings at the table even higher, faster.
