I'm guessing that you heated the "room" to 65 degrees just prior to applying the epoxy and held it that temp during the process and then shut the heat off and left the area. If that is the case the heat would have been still warming the wood and therefore outgassing. In my opinion the real trick is to stabilize the wood at whatever temp and then maintain that temp while applying the epoxy. When you're finished for the day then you may choose to lower the temp somewhat.

On the bright side these bubbles will gather and refract the light, sort of sparkle as they say. At least mine does