Now I may be giving him too much credit here, but it is possible that Gibbons really hates his job right now. When you want out of a terrible situation, you do things that make you look stupid and force the GMs hand.
Now most people would just suck it up or resign, but Gibbons isn't most people. So he figures he'll make unfavorable decisions to help open the emergency exit out of Toronto.
What about another possibility...was there a possible trade in the works that night to send Rios elsewhere and Gibbons was told not to play him at all that night???