Originally Posted by
NWIFlyer
From the description, and assuming the timetable for the corresponding Thursday in November 2018 is the same as November 2017, I think the OP's itinerary would have looked like the first screenshot, leaving at 11.05am and arriving in ITM at 6.15pm the following day.
The re-route on ANA (LHR-HND-ITM) was scheduled to arrive at 7.10pm - just 55 minutes late.
I'm also struggling a bit to understand what happened to make the OP "4.5 hours late" at ITM. After that flight that arrives at 1910, it looks like there are two more in the schedule for Friday evenings this season: 1900-2015 and 1920-2035. But to be 4½ hours late from an originally-booked scheduled arrival time of 1815, it would have had to have been at about 2245. So there would presumably have had to have been some further delay along the line.
However, on 16 November, NH212 was scheduled 1900-1550 and actual 1904-1531.
On 17 November:-
NH37 was scheduled 1800-1910, actual 1813-1921.
NH39 was scheduled 1900-2015, actual 1920-2032.
NH41 was scheduled 1920-2035, actual 1929-2043.
So I don't currently understand how the OP ended up at ITM 4½ hours late. It may be that he was booked on a much earlier NRT-ITM flight than the ITA screenshot shows, but given the paucity of information which is being provided by the OP, it's hard to know. If this is the standard of information which he is providing the BA agents, it may be that they too are finding it difficult to understand what the claim is, given that the original BA794 LHR-HEL only had a 19-minute arrival delay.
What does seem clear, though, is that if the OP had misconnected at HEL, as seemed very possible, there was quite a significant chance that he would have ended up not getting to Osaka on Friday evening at all.