Maybe, maybe not. There's just no way to verify that assertion. However, players can't be judged/ranked on what would happen if circumstances were different (precisely because there's no way to find out) but by actual performance. And based on actual performance, claiming RVP is the best striker in the world or even close is senseless. A few months of good form can't beat years of consistency. Not to mention even in the form of his life, he hasn't been the most prolific striker this season in Europe, and up until yesterday wasn't even the most prolific in his own league (can get back to that depending on what Kun does in the second half today).
This reminds me of when Torres was hailed as one of the world's best players a few seasons ago just because he had a great season, and then got brutally exposed. What about waiting until RVP even has that great complete season before making such bold proclamations?