Even trotting a horse to see if he is sound is not really a good enough check to be doing down at the start – the difference to how a horses uses himself between trotting and galloping is huge and you are much more likely to see an issue when doing the latter rather than the former.
Personally I’m not really sure this was the cause of the bad run – the horse is an out and out galloper and given the nature of the track and the more decent ground (4 of his 6 wins have been on soft or heavy ground) I felt he was always going to struggle today (a lot of his recent race descriptions mention the word ‘outpaced’ in them) and I am not sure if he is a G1 horse in the first place.
Think a race like the Coral Gold Cup at Newbury (especially on soft ground) would be more up his alley and eventually he could be a Welsh, Irish National, Bet365 or National type horse.