Yeah but that's pie in the sky nonsense. If you mean Starmer could be shoe-horned in as a caretaker PM. (Having read the article now, I don't think you mean that).
For a start, Starmer has ambitions. He wouldn't take that poisoned chalice if he could avoid it.
The excellent John Harris suggests that a voice for the poeple could be found outside the government, in the new leader of the opposition Kier Starmer, considering the disunity of the current administration. He said this before Boris went to hospital.
https://www.theguardian.com/commentisfree/2020/apr/05/boris-johnson-failed-unifying-leader-keir-starmer-coronavirus-crisis