Haven't seen the episode but it sounds like Bothriechis schlegelii, the eyelash viper. Found from Chiapas, Mexico on down through CA into northern SA. Found primarily in lowland coastal areas although there is one possible subspecies referred to as the mountain eyelash viper B. s. supraciliaris found only in Costa Rica.

Seeing that Redemption Island was filmed in Nicaragua this is a likely candidate.

See image below.
Image

-----
BigT
There is a difference between ignorance and stupidity. The ignorant can be taught, stupidity is beyond our control.
1.2 P. m. melanoleucus B/W N. J. Northern Pines
1.2 P. d. deppei Mexican Pines
2.2 P. l. lineaticollis Linis or Lined Pines
1.2 P. m. lodingi Black Pines
0.3 P. c. sayi red bulls
1.1 Drymarchon melenurus Blacktail Cribo
1.2 D. corais Yellowtail Cribos
1.2 M. s. cheynei Jungle Carpet
2.6 L. p. pyromelana Arizona Mt. Kings
1.1 L. g. californiae B/W Cali kings
0.0.3 M. f. flagellum Eastern Coachwhips
1.2 G. m. bottegoi Western Plated lizards