"I felt that we didn't get going at the start," said Hadden, whose side were looking to prevent Wales from recording only their second victory in Edinburgh in their last six visits.
"Then when we did seem to get going, the two guys who really led by example - Simon Webster and Geoff Cross - went off injured as a result of their efforts.
"And then when Geoff was sin-binned we were down to 14 men. Wales, like the top quality side they are, took full advantage of that and scored two tries.
"From there on it was an uphill struggle. But the killer blow came just after half-time."
Despite losing captain Ryan Jones through injury prior to kick off, Wales never looked like losing in the Scottish capital. Hadden's men worked hard for each other but the former Edinburgh coach felt they played into Welsh hands by not getting to grips with the game from the very start.
Hadden was pleased with the performance of players such as tryscorer Max Evans and record points scorer Chris Patterson who impressed after being called upon from the bench,but the damage had already been done by the time Evans's solo effort brought some respectability to the scoreline.
"Obviously, we knew we were playing the best side in the northern hemisphere, but it's disappointing that we allowed them to show what a good side they are," explained Hadden to BBC Scotland.
"We were going to come strong at one stage, but it took us too long to get going.
"We knew we had impact coming off the bench and it was disappointing we left them with such a mountain to climb.
"We had hoped that they would come on, give the boys a lift and take us home. There's no doubt that a couple of them put their hands up. But they had too much to do when they came on."