Cf. Lowe1962, 31: “this system of double marking, if used without the speakers’ names, could lead to ambiguity in rapid dialogue.”
Cf. Finglass2009, 338on S. Aj.  (with further references): “asyndeton . . . is found throughout tragedy and classical literature, but always as a particular stylistic feature. To give just two examples, it can introduce a brief maxim as an explanation, or juxtapose brief statements at moments of high emotion to give a pathetic effect. There is no such feature which could justify it here.” No-one, to my knowledge, has attempted to justify the asyndeton in our passsage: Allan and I are agreed that it is a fault that needs mending.