I agree that there could be chip dumping and/or collusion going on, and a penalty might be due to BOTH players.
Yes, the Floor should be called.
Since it seemed that Player A's intent was to put Player B all in, Player A should be required to make the call for the extra 2K.
On the other hand, since Player B incorrectly stated his stack size, Player B might be limited to a call of the 100K
No matter what the Floor's decision about that last 2K, both hands should be tabled, and the pot awarded to the better hand.