No. Restorer is quite right in the sense that Darwin did not theorize (or even systematically hypothesize) about the origin of life. The "warm pond" reference was a passing comment in a letter. It was a couple sentences in the context of (essentially), "but who the heck knows?"
Darwin never addressed the origin of life systematically and scientifically. And when Darwin DID address an issue systematically and scientifically, there was no doubting it. Typically he would fire off dozens of letters querying experts, open up notebooks, heavily notate books and articles (sometimes physically dismembering them in the process and sorting their pages into folders), conduct hundreds or even thousands of experiments personally, etc. No such effort, or any systematic effort, was ever devoted by Darwin to origin of life studies of any kind.
Here, btw, is the "warm little pond" comment. It's from an 1871 letter by Darwin to his friend, the botanist Joseph Hooker:
It is often said that all the conditions for the first production of a living organism are present, which could ever have been present. But if (and Oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc., present, that a protein compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.
In '63 Darwin had written to Hooker that:
It is mere rubbish thinking at present of the origin of life; one might as well think of the origin of matter.
Both quotes can be found here.
In his published works and his actual theorizing, Darwin ALWAYS treated life as axiomatic.
For instance only a year after the "warm pond" comment, in the 1872 edition of The Origin, Darwin explicitly presents the orgin of life as axiomatic, comparing it to gravity as something that must be taken for granted as existing with certain essential properties not themselves explained or accounted for by science (emphasis added):
It can hardly be supposed that a false theory would explain, in so satisfactory a manner as does the theory of natural selection, the several classes of facts above specified. It has recently been objected that this is an unsafe method of urguing: but it is a method used in judging of the common events of life, and has often been used by the greatest natural philosophers. The undulatory theory of light has been thus been arrived at; and the befief in the revolution of the earth on its own axis was until lately supported by hardly any direct evidence. It is no valid objection (to the theory of natural selection) that science as yet throws no light on the far higher problem of the essence or the origin of life. Who can explain the essence of the attraction of gravity? No one now objects to following out the results consequent on this unknown element of attraction; notwithstanding that Leihnitz formerly accused Newton of introducing "occult qualities and miracles" into philosophy.