I suppose you're right, in the strict sense of the word, yes.
Probably the main legacy of Latin from the Roman occupation of Britain is place names (such as the capital London itself of course). There must be quite a few other words that were adopted and remained, but that does not indicate the formation of a creole, you're right. Nor did the later Roman Catholic ascendency over the indigenous Celtic church succeed in making Latin anything more than an ecclesiastical (and largely written) language.
The succeeding waves of invaders: Angles, Saxons, Jutes, Danes, Vikings, etc; had more influence on the language than the Romans since they integrated and were common people not just administrators and nobles. This was often probably only local and dialectic though. The Normans had the greatest effect, yet, as you point out, they did not succeed in changing the language of Britain into a Latin one, largely because it was a top-down innovation.
