In today's environment - where email opens are very unreliable and often are a result of false-positives performed by email scanners - you shouldn't be doing anything when an email is opened. No scoring, no lead progression... nothing. Instead, you should be focusing on specific engagement/behaviors/scores to properly progress leads to MQL/MQC status. Just my $.02
Can you add a screenshot of your scoring campaign? Likely you can set up your scoring campaign to exclude these emails:
However I'll also have to agree with Dan Stevens. on this one. Email opens are pretty unreliable - probably wouldn't recommend using them for lead scoring.