On AY's own list weird flight numbers given to OUL:
Helsinki–Oulu 05 Oct 2015 AY2369
Oulu–Helsinki 05 Oct 2015 AY2370
and something weird with RVN 05OCT also:
A359 is AY421 HEL RVN 07:35-08:50 and return is AY428 13:50-15:10.
AY422 RVN-HEL 09:15-10:30 is now A319 and I cant see where is this aircraft coming from to RVN.
So there might be an error with A359 return. A359 can be AY422 or then AY 427 HEL-RVN.