Thanks for reporting this bug! I've fixed it for the next release that comes after v3.8.1.
Petrol Bomb power in stars Minimum Petrol Touch Decay for a softlock
-------------------------- -----------------------------------------
11 38
12 50
1 55
2 60
3 129
4 138
5 146
19 155
14 170
15 201
Your game had Petrol Bomb set to 1 star, so any Petrol Touch Decay of 55 or more would have potentially resulted in a softlock (with it being more and more likely the higher the value).
Note that this is a completely different bug than the one with high wind or low gravity which CyberShadow mentioned (which is documented in Known Issues in the v3.8 Readme).