SAP Development Manager interview questions

HR called directly for F2F interview. Reached on time and had one round which I thought went well. Questions were more around JVM memory, memory leak and then one question on algorithm (write code for it). Wrote the code and the interview was convinced (at least looked convinced) and then the interview ended and I was told to wait after which came the HR and said its negative and not going forward. I am still contemplating as to what happened :)