doing badly relatively and absolutely

NABI share price drops from 183 to 162 from day before announcement to yesterday. If you held at 183, you've lost 21 cents per share or 11.5%.
If you as a NABI shareholder want out of the deal you can get out at about a 5-10% discount to the price on announcement of the deal through the buyback.
BTA share price drops from 95 to 68 cents per share over those same landmarks, a loss of 27 cps or 28.4%.
If as a BTA shareholder you want out of the deal, well you sell on market at a 28.4% discount.
You really have to wonder.