Comparing the results of different languages is irrelevant, unless the exact same code is being compiled, using the exact same APIs and the EXE is being put together in the exact same way by the programming language.
One API call made wrong can flag AV programs. Some API calls done correctly will flag AV programs because it is an API rarely used by legitimate programs. An EXE put together in an abnormal order will flag an AV program. For example, Bob Zale made a change in one of the last versions of PB that started flagging AV programs. After two pages of arguments, he finally conceded he had mistakenly left something in that was resulting in an improper EXE that was flagging the AV programs. I have no idea if that bug was fixed and a patch issued before he died. For another example, using PB's Windows API includes which were written by Tom Hanlin will often flag AV programs, because many of the APIs are being called incorrectly. Use Jose's includes and the problem is solved, because Jose's includes are usually correct in the way they are calling the APIs.
And no, not anyone is free to test. Under the TOS and License of Virus Total, you can only upload software which you personally own the copyright on. Once uploading your test EXE there, you give Virus Total "royalty free, irrevocable and transferable licence to use, edit, host, store, reproduce, modify, create derivative works, communicate, publish, publicly perform, publicly display and distribute such content."
Most people would not give away all rights to their software in this manner. What is worse is when people will download an application or game you have written and upload it to Virus Total in direct violation of your copyright and in blatant violation of the TOS of Virus Total. This results in several hundred dollars in legal fees for you to get a pull down request issued under the DMCA to Virus Total which is in another country.
