What happened here?

[FA Limited]

got some stuff back from the lab today developed and scanned. the last few frames had this similar problem. is this just not cleaned properly? coincidentally i used a hoya XO filter at the same time, but i don't think it could cause something like this?

 

[ChrisN]

I'd try washing the neg again - it looks like crud left over from the final rinse.

 

[FA Limited]

thanks chris, i'll check that out!

 

[ChrisN]

If it doesn'r wash off, then I'd say the developer (or maybe the fixer?) was all froth and bubbles. But I don't know how that would effect only the last few frames. Either way it looks like the lab did a poor job.