Without discussion I would assume 3N was an offer to play and 4m is a natural slam try. It's possible 5H shows this but most would be very hesitant to bomb past Blackwood and cramp the auction.
I agree that 6♥ was a bad bid but I think East's 5♣ bid is such a gross overstatement it deserves 99% of the blame. Also by the time the partnership had bid to the five level this was already a bad board.
In fairness, it is understandable that good players would have this misunderstanding. East thought that he had limited his hand by not making a slam try immediately over 3♠ (I disagree - I think he can be big and balanced). He then thought that, as West was unlimited, he owed ...
East (pass of 3♠): I don't have a hopeless hand.
West (pass of 4♠): I'm not sure whether to bid on or defend 4Sx.
East (5♣): I have a slam try??
100% East.
Hi Kiat. I am very interested in this idea and have been thinking about it for some time. If you do decide to get a group together please keep me in the loop!