He was only somewhat abashed, however, and later, when he met Harry, he tried to explain along with his half-hearted apology (OP).

不过于此他自己只是有点窘迫，事后碰见哈利，他还试图为自己开脱，仅仅对他做了个没甚诚意的道歉(凤凰社)。

youdao

Should you ask why? Should you make a case for yourself? Should you scream "APRIL FOOL'S" and run away? For now, all you can do is mouth a half-hearted "oh" as they stammer out an apology.

你应该问为什么吗?你应该为你自己找借口吗?你应该边喊愚人节边跑开吗?现在，所有你能做的是吞下半颗心的“哦”在她们结巴的说出道歉之前。

youdao

United Daily News says Taipei must not be "half-hearted" on demanding a formal apology and compensation.

BBC: China media: Philippines row

But Alan Leighton, head of Prospect, felt Ferguson's apology had been "half-hearted" and is disappointed by the ruling, believing the authorities missed an opportunity to make a statement to back up the FA's Respect campaign.

BBC: Ferguson hit with FA fine and ban