Wrong. Yediruppa bpought 6 independents and made 5 of them Cabinet Ministers. That was before the trust vote.
So getting opposition MLAs to defect, made Ministers and stand for re-elections are OK, then if 20 BJP MLASs resign and bring down the Yediruppa govt, is also OK.
There is huge dissatisfaction among traditional BJP loyalists who had been passed over in Ministrial berths. The probability of a huge split within BJP is high