That's theorically true, but it misses the point that they didn't know what the problem was (that it was the battery) and they didn't know that the batteries that they tested and thought were safe for the second round had a totally different problem that had similar results. So they could have attempted that, replaced just the batteries, probably had a higher retention rate of phones in the wild and saved money up front - only to carry a boatload more risk, have disastrous results and have to recall the devices anyways. It also discounts the smaller number of people that would have participated in the recall without it being heavily pushed on them, which also increases the risk. The bottom line is that without having the knowledge we have now and having it 9 months ago, Samsung would not have been able to get away with only recalling the battery and if they did attempt to do so, it's likely they would have seen far worse results. That's not a decision they'd be able to justify (at the moment) in any way because that knowledge wouldn't have been available in a timely fashion.