Following up MDL-75688, I noticed that the log table had an index that might potentially cause issue when inserting rows.

The original change is here: https://github.com/blindsidenetworks/moodle-mod_bigbluebuttonbn/commit/0891999129b2adaa27d641935ecc3ce0ee5ed1ae

But looking at the current queries, I don't see any existing justification to keep it.