We have to be fair, and we have to be seen to be fair.
Absolutely! I doubt the Israeli ship was just on a pleasure cruise, so the Lebanese have the right to self defence irrespective of the reason behind it. The fact that they buy Iranian is irrelevant and far less in need of retaliation than, say, the US directly supplying Stingers to the mujahideen for the only purpose of firing at Russian personnel.
The West are masters of double standards and that's half the reason we're so increasingly despised.