Currently, parenscript cells with unmatched parens end up getting evaluated as object rather than being flagged with an error. This causes problems when the programmer assumes a cell evaluated properly. Check for balanced parens before doing the thing.
From #67:
Currently, parenscript cells with unmatched parens end up getting evaluated as object rather than being flagged with an error. This causes problems when the programmer assumes a cell evaluated properly. Check for balanced parens before doing the thing.