Owner says he only let the other company brand the product with the Gold Apollo name. I think that makes it his product legally, at least partly, if not fully, even if it is not technically his product.
The owner is not responsible for the explosions if he did not know someone put it in them. He could know, but it is very unlikely he would ruin his company's name and be charged with a crime.
Who in Pakistan would use a Bharati manufactured phone instead of a Chinese one? Perhaps wishful Muhajir neo-liberals & elite class Sindhi leftists but that's about it.