Negligence is a proximate cause of an injury if it was a
substantial factor in bringing the injury about.
Winn v. Posades, 281 Conn. 50, 56
(2007); see also Pilon v. Alderman, 112 Conn. 300, 301-302 (1930) ("The
meaning of the term ‘substantial factor' is so clear as to need no expository
definition . . . . Indeed, it is doubtful if the expression is susceptible of
definition more understandable than the simple and familiar words it employs.");
Phelps v. Lankes, 74 Conn. App. 597, 606-607 (2003) (same).