It's very late ( UK) and I'm very tired so Ill keep this short in case you're feeling anxious and awaiting a reply ..
First off he will be fine .... they're very tough !
The second strike sounds like a little defensive strike from a nervous little guy... he may also be going into shed mode which would also explain it . I'd relax and leave him alone for a week or so to settle down ..
They can stay underwater for about 30 minutes apparently so that 15 seconds is nothing ... They remain still as a defence reaction .. they often ball up hence the name ( which I hate ) . I prefer our UK version of Royal .