It looks like the conversion should have given double the amount of Steem as the amount of SBD (roughly speaking) seeing as, again roughly speaking, the cost was half.

It appears to me as though INSTEAD, your friend received HALF the amount of Steem instead of double.

My guess is somewhere in the algorythm or in the covnersion, something messed up the calculations and did everything backwards.

Was this done with Blocktrades or directly in Steemit? I'm not sure which Discord chat can help, but I'm sure there is one for such bugs.

I will resteem this, in the hopes that someone knows where you can make you "complaint", well your friend, so that he can be compensated with his missing Steem.

It's weird how this happened, but it's clear to me the system did a whole backwards calculation thing and that is seriously messed up, man.