The sequence of tenses often depends on context and timing. Without other evidence, I don't find anything unusual about your sentence.
Student or Learner
I was reading an article on Reuters about a government official who had been sacked for corruption.
There was a one-line paragraph that had an unusual sentence construction, at least to my eyes:
While several senior heads have rolled, no senior diplomats had been caught up.
The subordinate clause, which is written in present perfect, is followed by the main clause written in past perfect.
Is the sequence of verb tenses, or combination of present perfect and past perfect, grammatically correct? Is such sentence construction common in English?
Welcome to the forum, Vinko.
I think we need to read the previous sentence before we can comment definitively on the one you quoted.
Here is the paragraph that comes just before the one-line paragraph:
President Xi Jinping has cracked down on corruption since assuming office two years ago, warning, as others have before him, that the problem is so bad it could affect the Communist Party's ability to maintain power.
For the complete article, the link is http://www.reuters.com/article/2015/...0KB03M20150102.
I agree with you Vinko that it sounds odd. Having taught English in Hong Kong, it sounds like a frequent error made by HK Chinese speakers, who often use the present perfect for the preterite, and who also frequently use the pluperfect for the present perfect.