I saw the replay a few times and am not so sure it was that obvious. It certainly looks that way because of the offending (allegedly) skater lifting his leg, but I couldn't tell whether the skate came off the ice before or after the puck entered the zone completely.
Either way, though, they really should have spent a little more time reviewing it seeing as how close it appeared. I get the feeling they didn't even review the offsides at all. I think they reviewed the entry of the puck into the net. Shame on them.
Regardless, the Tigers didn't lose because of a blown offsides call. They lost because they "...had no answer to 13" as stated by Coach Wilson. McLaughlin was pretty spectacular on Friday. Thankfully, the Tigers were able to contain him on Saturday.