Americans in Paris

I think there's a difference between knowing some English and being able to talk to someone in English.  In this scenario I guess you knew enough French to understand what they were saying but not enough to ask them in French?  Maybe they were in the same situation, having enough English to get the jist of what you wanted but not enough to actually help you?

A 'modern foreign language' has been (on and off) a compulsory GCSE subject for 20-odd years in this country so I'd guess that most people fall into the above category.  Take me for example, I know enough Spanish to order a couple of beers and a ham sandwich so if a Spaniard over heard me, they wouldn't be to far off the mark to assume I spoke some Spanish... but if he were to come over to me and ask for my help the chances of me knowing what he wanted would be slim (maybe I could pick out the odd word) and the chances of me knowing enough Spanish to construct an answer would be slimmer.

That's a fair enough assessment for British/American citizens who don't generally speak a second language well (since in general British kids only learn French or German between the ages of 11 and 16 - something I think should be taught in primary school as well), but in France, many people learn English from a young age, meaning that they end up being competent or even fluent in English by the time they leave school - and so are more likely to be able to speak good English to you than you can speak good French to them.

I have two friends from Belgium, one is fluent in both English and French and is competent in Dutch, while the other is fluent in English, French and German. In fact, in Belgium, they prefer to speak in English to you and that you speak English to them (especially in the Flemish-speaking regions) - often they won't even acknowledge you if you try to speak in French to them!

More French people probably speak good English than vice-versa but certainly not all do. 

Belgium is a very different case than France, being a small, multilingual country - it is necessary to be a polyglot to be successful.  Many French people are monolingual for the  same reason that we are, they have enough domestic industry and home grow media to make a foreign language unnecessary.

It is entirely possible that every Frenchman speaks prefect English but refuses to to out of spite...  but I'm a great believer in the simple answer most often being right.

I was just hypothesising that if British tourists who spoke no/little French visited a small town where people rarely encountered English tourists, the locals might be less willing/able to speak in English to them compared to somewhere like Paris - I could understand if that happened and then was interpreted as the French being rude because they wouldn't speak English.

Could be. I don't know as I speak French and wouldn't ever spout off in English.. I did meet a friend's girlfriend  in the Charentes region who literally didn't know a word of English. She was a lot older (mid 60's ish) but I remember being amazed that she didnt know any English... maybe my american imperialism coming thru.