Obviously we couldn't see this match live, but from the match stats, Jamie was clearly the more consistent player until *5-4 in the second set, without a single break point conceded. Then Sugita broke when he had to, and took control of the match....4 breaks to 1 from that point (including a few scares late in the second and early in the third). I suspect this must be a fast court (38 aces for Oswald, 12 for Jamie!) which should give the less powerful server like Jamie an extra boost, but that wasn't helping Jamie hang on towards the end.
I did have the chance to watch the stream of Jamie versus J-L Struff of Germany at Loughborough (finalist there and semi finalist the next week at the much tougher Helsinki Challenger - a very good player, but unlikely ever to be top 50). It was OK for a while, as Struff got his range and took a look at Jamie's serve and overall game. Jamie clearly has good groundstrokes, good point construction, and a fighter's spirit. But not much power and no real weapons. Once Struff started to open his shoulders he literally blew Jamie off the court, from return of serve onwards. The difference in power was quite extraordinary - anything short got lasered, without Struff even having to go close to the lines.
Heather seems to have adapted her training to add more serve/groundstroke power to her armoury (and she also has the willingness to unleash it more often in matches, unlike a Wozniacki) and I really think Jamie could make bigger strides than previously if he took a similar approach. He's only a few points per match away from very good results. Perhaps winter training with Andy will help in this regard.