OK - so you've now experienced the variability in quality of interviewers in commerce/industry, since the purpose of an interview should be to allow the interviewee a good amount of time to explain themselves and give examples that support their knowledge and competences. A good ratio of total time taken is probably about 3:1 but I don't suggest that you start timing!
If there are two things in life that everyone seems to think they are good at, it is sex and making people judgements. IMHO the latter is generally false (ever come across Johari Window? - try Googling it) - not sure about the former.
The general format of the interview often starts with a short intro to the job from the interviewer, but this also acts to steady the nerves of the candidate. It is bad news if one doesn't let the interviewee start their piece soon - maybe 5 minutes max. The front end should be used to expand on what the 'list of duties' may have said - not repeat it.
Maybe just nod encouragingly to try and get the interviewer to be quiet.
Maybe, if you can get a word in edgeways "I think I've the general gist of the job, thanks, would it help if I outlined a couple of examples of experiences where I have done a similar sort of thing".
Questions such as "do you think you could do that?" are clearly bad news since they invite the answer yes or no. As I'm sure you appreciate, interviewer should be saying "how do you think you could measure up to that" - or similar.
Good luck.