Yes, I experience this occasionally - it is mostly if windy, then the wind can "hold" the hydrofoil on its side working as a sail
Can always bodydrag to the board, but normally when mast down I don't need to as the hydrofoil dolphins downwind fast when small (or bigger) waves - so you get lazy and just drag sideways a bit down maybe both hands on the bar and wait for the board
But when on its side you have to bodydrag for real like if going for a TT board
Quite amazing even though rare.
Good thing is, board is ready for you to take off immediately just put your feet up and go
I wish there was a hydrofoil that only did this when low water close to shore, so it would not ding on the bottom nor run ashore too fast - would be genius
PS: On the plus side is, that it means you got a low weight foil so often when you crash, or miss a trick, it sinks really slow as opposed to alufoils, so you can just start again right away because it is still on its side - great when strapless, superfast and I love that