Doc, you must be wrong.
3 seconds sound clip from the Carry On Screaming! movie soundboard.
You can hear this line at 00:28:12 in the Blu-ray version of the movie.
Quote context
[...]
- Homo gargantuoso. Homo... Aye. Well... whew. Erm... that's the wrong homo.
- Ah. Homo gargantuoso. Here it is.
- Well, the finger looks the same.
- Aye, that's the one. It's extinct now, of course.
- Are you saying that... this finger's come off something that's been dead for 500 years?
- No doubt about it. Dead as a doornail.
- That finger came off something that was alive last night anyway.
- Well, you do that, will you?
- This was pushed through my letterbox this morning.
- Dear Sir, if you want to know what happened to Doris Mann, I can tell you.
- I am the cloakroom attendant at the one by the park, and you can see me any time at my convenience.
[...]