Its not like all the ships hit by attacks in the Straight of Hormuz sank. A ship could potentially become critically damaged and become unable to operate the reactor and still be floating.

Either way, "loss of nuclear material" is the real concern isn't it, instead of just the nature of how that loss happened?

The question still stands. If a country knows they're potentially going to cause a nuclear disaster by hitting one of these ships on their shoreline, are they as likely to shoot at them?

The hardliners might want to cause a nuclear incident to keep the strait closed longer.

And even among the non-hardliners mistakes are rampant in war. It's not about what they're likely to rationally do, it's about what some local, demoralized missile officer who graduated in the bottom 20% of his class does when he's cut off from command and drinking too much.