I'm assuming that will apply also in my case for SYD-BKK-IST-LGW (TG then TK, TK) where my connection is now 5 mins under MCT at 70 mins -- if misconnect they will put the pax on the next flight? Who is "they" -- i.e. TK (because they are the onward carrier) desk or TG (because they were late)?

Next TK BKK-IST flight is only around 12 hours later at 11am -- would they pay for hotel overnight -- I assume so based on past experience with revenue flights.

Finally -- would they have any chance (assuming they are not much too late) to persuade TG to let them on the 0015 flight 30 mins later than the TK? (Back to LHR rather than LGW, but that's actually better.). Actually the direct TG flight at 1330 would still get them back to London earlier than indirect via IST...