He misplayed against you, and you got very lucky with the number of bullet seed hits. Bullet Seed: 25.89 - 30.35% for 3 hits on your spread, which breaks the sub. Mach Punch: 55.65 - 65.47%, which leaves you with 50% at best if your sub was broken.Here is a replay of the last few Breloom's I faced. Only have exported text sorry.
Start of turn 1
Ninjask used Substitute!
Ninjask made a substitute!
The foe's Breloom used Swords Dance!
The foe's Breloom's Attack sharply rose!
Ninjask's Speed Boost increases its speed!
Ninjask's Speed rose!
Start of turn 2
Ninjask used Baton Pass!
JG is ME called Ninjask back!
JG is ME sent out Scizor!
The foe's Breloom used Bullet Seed!
It's not very effective...
Scizor's substitute took the damage!
Scizor's substitute took the damage!
Hit 2 time(s)!
The foe's Breloom is hurt by its Life Orb!
Start of turn 3
Scizor used Iron Defense!
Scizor's Defense sharply rose!
The foe's Breloom used Swords Dance!
The foe's Breloom's Attack sharply rose!
Start of turn 4
The foe's Breloom used Mach Punch!
Scizor's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Scizor used Iron Defense!
Scizor's Defense sharply rose!
Start of turn 5
The foe's Breloom used Mach Punch!
Scizor lost 103 HP! (30% of its health)
The foe's Breloom is hurt by its Life Orb!
Scizor used Substitute!
Scizor made a substitute!
Scizor restored a little HP using its Leftovers!
Start of turn 6
The foe's Breloom used Mach Punch!
Scizor's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Scizor used Baton Pass!
JG is ME called Scizor back!
JG is ME sent out Espeon!
Start of turn 7
Espeon used Stored Power!
It's super effective!
A critical hit!
The foe's Breloom lost 60% of its health!
The foe's Breloom fainted!
Start of turn 1
Ninjask used Substitute!
Ninjask made a substitute!
The foe's Breloom used Swords Dance!
The foe's Breloom's Attack sharply rose!
Ninjask's Speed Boost increases its speed!
Ninjask's Speed rose!
Start of turn 2
The foe's Breloom used Mach Punch!
It's not very effective...
Ninjask's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Ninjask used Baton Pass!
JG is ME called Ninjask back!
JG is ME sent out Scizor!
Start of turn 3
Scizor used Substitute!
Scizor made a substitute!
The foe's Breloom used Spore!
Scizor's substitute blocked Spore!
Scizor restored a little HP using its Leftovers!
Start of turn 4
The foe's Breloom used Mach Punch!
Scizor's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Scizor used Iron Defense!
Scizor's Defense sharply rose!
Scizor restored a little HP using its Leftovers!
Start of turn 5
The foe's Breloom used Mach Punch!
Scizor lost 108 HP! (32% of its health)
The foe's Breloom is hurt by its Life Orb!
Scizor used Substitute!
Scizor made a substitute!
Scizor restored a little HP using its Leftovers!
Start of turn 6
The foe's Breloom used Mach Punch!
Scizor's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Scizor used Baton Pass!
JG is ME called Scizor back!
JG is ME sent out Espeon!
Start of turn 7
The foe's Breloom used Mach Punch!
It's not very effective...
Espeon lost 75 HP! (22% of its health)
The foe's Breloom is hurt by its Life Orb!
Espeon held up its Red Card against the foe's Breloom!
The foe's Espeon was dragged out!
Espeon used Stored Power!
It's not very effective...
The foe's Espeon lost 17% of its health!
Start of turn 1
Ninjask used Substitute!
Ninjask made a substitute!
The foe's Breloom used Swords Dance!
The foe's Breloom's Attack sharply rose!
Ninjask's Speed Boost increases its speed!
Ninjask's Speed rose!
Start of turn 2
Ninjask used Baton Pass!
JG is ME called Ninjask back!
JG is ME sent out Scizor!
The foe's Breloom used Swords Dance!
The foe's Breloom's Attack sharply rose!
Start of turn 3
The foe's Breloom used Mach Punch!
Scizor's substitute faded!
The foe's Breloom is hurt by its Life Orb!
Scizor used Iron Defense!
Scizor's Defense sharply rose!
Start of turn 4
The foe's Breloom used Mach Punch!
Scizor lost 165 HP! (49% of its health)
The foe's Breloom is hurt by its Life Orb!
Scizor used Baton Pass!
JG is ME called Scizor back!
JG is ME sent out Espeon!
Start of turn 5
Espeon used Stored Power!
It's super effective!
The foe's Breloom lost 80% of its health!
The foe's Breloom fainted!
Let me know what other scenario you think could bring about trouble and I can try to analyze what I would do in that situation. So far I don't have much trouble with Breloom though.
Since he didn't break your sub due to a 33% chance, he should have simply set up alongside you to +4 or 6, in which case all he needs to do is spam bullet seed. 252 Atk Life Orb Technician Breloom Bullet Seed (3 hits) vs. 252 HP / 248+ Def Espeon: 234-282 (70.05 - 84.43%) -- guaranteed 2HKO, what happens if he gets 4 or 5 hits on you? You are faster than him, so spamming bullet seed is guarenteed to hit espeon, which has no recovery outside moonlight, which against rain/sand/hail is only 25%.
Put simply you got very lucky, especially since he wasn't adamant like he should be, or potentially focus sashed.